HELP PRECALC I DO NOT UNDERSTAND AT ALLLLL!!!!!!!!!!!!!!!!!!!!!!

HELP PRECALC I DO NOT UNDERSTAND AT ALLLLL!!!!!!!!!!!!!!!!!!!!!!

Answers

Answer 1

Answer:

  φ ≈ 1.19029 radians   (≈ 68.2°)

Step-by-step explanation:

There are simple formulas for A and φ in this conversion, but it can be instructive to see how they are derived.

We want to compare ...

  y(t) = Asin(ωt +φ)

to

  y(t) = Psin(ωt) +Qcos(ωt)

Using trig identities to expand the first equation, we have ...

  y(t) = Asin(ωt)cos(φ) +Acos(ωt)sin(φ)

Matching coefficients with the second equation, we have ...

  P = Acos(φ)

  Q = Asin(φ)

The ratio of these eliminates A and gives a relation for φ:

  Q/P = sin(φ)/cos(φ)

  Q/P = tan(φ)

  φ = arctan(Q/P) . . . . taking quadrant into account

__

We can also use our equations for P and Q to find A:

  P² +Q² = (Acos(φ))² +(Asin(φ))² = A²(cos(φ)² +sin(φ)²) = A²

  A = √(P² +Q²)

_____

Here, we want φ.

  φ = arctan(Q/P) = arctan(5/2)

  φ ≈ 1.19029 . . . radians


Related Questions

A right triangle has legs with lengths equal to 10 inches and 9x inches. Its hypotenuse measures (x + 10) inches. What is the approximate value of the hypotenuse? 10 inches 10.25 inches 20.25 inches 81 inches

Answers

Answer:

10.25 inches

Step-by-step explanation:

Given,

Perpendicular ( p ) = 9x

Base ( b ) = 10

Hypotenuse ( h ) = x + 10

Now, let's find the value of x

Using Pythagoras theorem:

[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]

Plug the values

[tex] {(x + 10)}^{2} = {(9x)}^{2} + {(10)}^{2} [/tex]

Using [tex] {(a + b)}^{2} = {a}^{2} + 2ab + {b}^{2} [/tex] , expand the expression

[tex] {x}^{2} + 20x + 100 = {(9x)}^{2} + {10}^{2} [/tex]

To raise a product to a power , raise each factor to that power

[tex] {x}^{2} + 20x + 100 = 81 {x}^{2} + {10}^{2} [/tex]

Evaluate the power

[tex] {x}^{2} + 20x + 100 = 81 {x}^{2} + 100[/tex]

Cancel equal terms on both sides of the equation

[tex] {x}^{2} + 20x = 81 {x}^{2} [/tex]

Move x² to R.H.S and change its sign

[tex]20x = 81 {x}^{2} - {x}^{2} [/tex]

Calculate

[tex]20x = 80 {x}^{2} [/tex]

Swap both sides of the equation and cancel both on both sides

[tex]80x = 20[/tex]

Divide both sides of the equation by 80

[tex] \frac{80x}{80} = \frac{20}{80} [/tex]

Calculate

[tex]x = \frac{20}{80} [/tex]

Reduce the numbers with 20

[tex]x = \frac{1}{4} [/tex]

The value of X is [tex] \frac{1}{4} [/tex]

Now, let's replace the value of x to find the approximate value of hypotenuse

Hypotenuse = [tex] \frac{1}{4} + 10[/tex]

Write all numerators above the common denominator

[tex] \frac{1 + 40}{4} [/tex]

Add the numbers

[tex] \frac{41}{4} [/tex]

[tex] = 10.25[/tex] inches

Hope this helps..

best regards!!

Answer:

10.25

Step-by-step explanation:

because I said so ya skoozie

A group of patients select from among 38 numbers, with 18 odd numbers (black) and 18 even
numbers (red), as well as 0 and 00 (which are green). If a doctor pays $7 that the outcome is an odd
number, the probability of losing the $7 is 20/38 and the probability of winning $14 (for a net gain of
only $7, given you already paid $7) is 18/38
If a doctor pays $7 that the outcome is an odd number, how would you figure out what is the doctors
expected value is?

Answers

Answer: $2.95

Step-by-step explanation:

Given: Probability of losing the $7 = [tex]\dfrac{20}{38}[/tex]

Probability of winning $14  = [tex]\dfrac{18}{38}[/tex]

Then, the expected value = (- $7)  x ( Probability of losing the $7) + $14 x(Probability of winning $14)

= [tex](-\$ 7)\times\dfrac{20}{38}+(\$14)\times\dfrac{18}{38}[/tex]

= [tex]-\dfrac{70}{19}+\dfrac{126}{19}[/tex]

= [tex]\dfrac{56}{19}\times\approx\$2.95[/tex]

∴ If a doctor pays $7 that the outcome is an odd number, the doctor's

expected value is $2.95.

Solve 2x^2 + x - 4 = 0
X2 +

Answers

Answer:

[tex]\large \boxed{\sf \ \ x = -\dfrac{\sqrt{33}+1}{4} \ \ or \ \ x = \dfrac{\sqrt{33}-1}{4} \ \ }[/tex]

Step-by-step explanation:

Hello, please find below my work.

[tex]2x^2+x-4=0\\\\\text{*** divide by 2 both sides ***}\\\\x^2+\dfrac{1}{2}x-2=0\\\\\text{*** complete the square ***}\\\\x^2+\dfrac{1}{2}x-2=(x+\dfrac{1}{4})^2-\dfrac{1^2}{4^2}-2=0\\\\\text{*** simplify ***}\\\\(x+\dfrac{1}{4})^2-\dfrac{1+16*2}{16}=(x+\dfrac{1}{4})^2-\dfrac{33}{16}=0[/tex]

[tex]\text{*** add } \dfrac{33}{16} \text{ to both sides ***}\\\\(x+\dfrac{1}{4})^2=\dfrac{33}{16}\\\\\text{**** take the root ***}\\\\x+\dfrac{1}{4}=\pm \dfrac{\sqrt{33}}{4}\\\\\text{*** subtract } \dfrac{1}{4} \text{ from both sides ***}\\\\x = -\dfrac{1}{4} -\dfrac{\sqrt{33}}{4} \ \ or \ \ x = -\dfrac{1}{4} +\dfrac{\sqrt{33}}{4}[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

"Radon: The Problem No One Wants to Face" is the title of an article appearing in Consumer Reports. Radon is a gas emitted from the ground that can collect in houses and buildings. At certain levels it can cause lung cancer. Radon concentrations are measured in picocuries per liter (pCi/L). A radon level of 4 pCi/L is considered "acceptable." Radon levels in a house vary from week to week. In one house, a sample of 8 weeks had the following readings for radon level (in pCi/L). 1.92.45.75.51.98.23.96.9 (a) Find the mean, median, and mode. (Round your answers to two decimal places.) mean 4.55 median 4.7 mode 1.9 (b) Find the sample standard deviation, coefficient of variation, and range. (Round your answers to two decimal places.) s CV % range (c) Based on the data, would you recommend radon mitigation in this house

Answers

Answer:

a) Mean = 4.55

   Median = 4.7

   Mode = 1.9

b) S =  2.3952

   CV = 52.64 %

   Range = 6.3

c) Yes, since the average and median values are both over "acceptable" ranges.

Step-by-step explanation:

Explanation is provided in the attached document.

Test the given claim. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, and then state the conclusion about the null​ hypothesis, as well as the final conclusion that addresses the original claim. Among 2160 passenger cars in a particular​ region, 243 had only rear license plates. Among 358 commercial​ trucks, 55 had only rear license plates. A reasonable hypothesis is that commercial trucks owners violate laws requiring front license plates at a higher rate than owners of passenger cars. Use a 0.05 significance level to test that hypothesis. a. Test the claim using a hypothesis test. b. Test the claim by constructing an appropriate confidence interval.

Answers

Answer:

For 0,90 of Confidence we reject H₀

For  0,95 CI we reject H₀

Step-by-step explanation:

To evaluate a difference between two proportion with big sample sizes we proceed as follows

1.-Proportion 1

n = 2160

243 had rear license  p₁ = 243/2160     p₁ = 0,1125

2.Proportion 2

n = 358

55   had rear license   p₂ = 55/ 358     p₂ = 0,1536

Test Hypothesis

Null Hypothesis                            H₀      ⇒   p₂   =  p₁

Alternative Hypothesis                Hₐ     ⇒    p₂  >  p₁

With signficance level  of  0,05  means  z(c) = 1,64

T calculate   z(s)

z(s) =  ( p₂ - p₁ ) / √ p*q ( 1/n₁  +  1/n₂ )

p = ( x₁  +  x₂ ) / n₁  +  n₂

p = 243  +  55 / 2160 + 358

p = 0,1183     and then    q = 1 -  p     q =  0,8817

z(s) =  ( 0,1536 - 0,1125 ) / √ 0,1043 ( 1/ 2160   +  1 / 358)

z(s) =  0,0411 /√ 0,1043*0,003256

z(s) = 0,0411 / 0,01843

z(s) =  2,23

Then  z(s) > z(c)      2,23  >  1,64

z(s) is in the rejection region we reject H₀

If we construct a CI for  0,95   α = 0,05   α/2  =  0,025

z (score ) is  from z- table    z = 1,96

CI = ( p ±  z(0,025*SE)

CI = ( 0,1536 ± 1,96*√ 0,1043*0,003256 )

CI = ( 0,1536 ± 1.96*0,01843)

CI = ( 0,1536 ± 0,03612 )

CI = ( 0,11748  ;  0,18972 )

In the new CI we don´t find  0 value so we have enough evidence to reject H₀


Find the perimeter of an equilateral triangle where area is 72cm. ​

Answers

Answer:

38.68 cm

Step-by-step explanation:

Perimeter of an equilateral triangle : P = 3a

Area of an equilateral triangle : A = [tex]\frac{\sqrt{3} }{4}a^2[/tex]

a = side length

The area is given, solve for a.

[tex]72= \frac{\sqrt{3} }{4}a^2[/tex]

[tex]a = 12.894839[/tex]

The side length is 12.894839 centimeters.

Find the perimeter.

P = 3a

P = 3(12.894839)

P = 38.684517 ≈ 38.68

The perimeter is 38.68 centimeters.

Is the given triangle scalene, isosceles, or equilateral? The Vertices are T(1,1), V(4,0), S(3,5)

Answers

Answer: It is a scalene triangle.

Step-by-step explanation:

It is scalene because the length between T and V are not equal,the length between T and S is not equal and the length between V and S is also not equal. All the side lengths of the triangle have different measures.

Find the equation of a line that contains the points (−2,2) and (−6,−5). Write the equation in slope-intercept form, using fractions when required.

Answers

Answer:

[tex]4y - 7x - 1 = 0[/tex]

[tex]m = \frac{y2 - y1}{x2 - x1?} [/tex]

[tex]m = \frac{ - 5 - 2}{ - 6 - - 2?} [/tex]

[tex]m = \frac{ - 7}{ - 4} [/tex]

[tex]m = \frac{7}{4} [/tex]

[tex]y = m(x - x1) + y1[/tex]

[tex]y = \frac{7}{4} (x + 2) + 2[/tex]

[tex]y = \frac{7}{4} x + \frac{7}{2} + 2[/tex]

[tex]y = \frac{7}{4} x + \frac{11}{2} [/tex]

[tex]4y = 7x + 22[/tex]

[tex]4y - 7x - 22 = 0[/tex]

The equation of the line passing through the point (-2,2) and (-6,-5) is,

y = (-7/4)x +(11/2).

What is an equation of the line?

An equation of the line is defined as a linear equation having a degree of one. The equation of the line contains two variables x and y. And the third parameter is the slope of the line which represents the elevation of the line.

The general form of the equation of the line:-

y = mx + c

m = slope

c = y-intercept

Slope = ( y₂ - y₁ ) / ( x₂ - x₁ )

Given that the equation of a line that contains the points (−2,2) and (−6,−5).

Calculate the slope of the line,

Slope = ( y₂ - y₁ ) / ( x₂ - x₁ )

Slope = ( -5-2) / (-6 + 2 )

Slope= 7 / 4

The y-intercept is calculated as,

y = mx + c

2 = (-7/4) x 2 + c

c = 11 / 2

The equation will be written as,

y = mx + c

y = (7 / 4)x + (11/2)

Therefore, the equation of the line passing through the point (-2,2) and (-6,-5) is,

y = (-7/4)x +(11/2).

To know more about an equation of the line follow

https://brainly.com/question/18831322

#SPJ2

Which equation shows function g in factored form?


g(x) = 2x^2 – 6x – 56

O A. g(x) = 2(x-4)(x + 7)

OB.g(x) = 2(x2-3x-28)

OC. g(x) = (2x + 7)(x-8)

OD. g(x) = 2(x + 4)(x - 7)​

Answers

Answer:

[tex]\boxed{\sf Option \ D}[/tex]

Step-by-step explanation:

[tex]\sf g(x) = 2x^2-6x-56\\[/tex]

Factorizing using mid term break formula

[tex]\sf g(x) = 2x^2-14x+8x-56\\g(x) = 2x(x-7)+8(x-7)\\g(x) = (2x+8)(x-7)\\g(x) = 2(x+4)(x-7)[/tex]

What is the focus of the parabola? y=−1/4x2−x+3

Answers

Answer:  Focus = (-2, 3)

Step-by-step explanation:

[tex]y=-\dfrac{1}{4}x^2-x+3\\\\\rightarrow a=-\dfrac{1}{4},\ b=-1[/tex]

First let's find the vertex. We do that by finding the Axis-Of-Symmetry:

[tex]AOS: x=\dfrac{-b}{2a}\quad =\dfrac{-(-1)}{2(\frac{-1}{4})}=\dfrac{1}{-\frac{1}{2}}=-2[/tex]

Then finding the maximum by inputting x = -2 into the given equation:

[tex]y=-\dfrac{1}{4}(-2)^2-(-2)+3\\\\y=-1+2+3\\\\y=4[/tex]

The vertex is: (-2, 4)

Now let's find p, which is the distance from the vertex to the focus:

[tex]a=\dfrac{1}{4p}\\\\\\-\dfrac{1}{4}=\dfrac{1}{4p}\\\\\\p=-1[/tex]

The vertex is (-2, 4) and p = -1

The focus is (-2, 4 + p) = (-2, 4 - 1) = (-2, 3)

P(x)=2x^5+9x^4+9x^3+3x^2+7x-6;x=i,-2

Answers

Answer:

The value of the polynomial function at P(1) and P(-2) is 24 and 0 respectively.

Step-by-step explanation:

We are given with the following polynomial function below;

[tex]\text{P}(x) = 2x^{5} +9x^{4} +9x^{3} +3x^{2}+7x-6[/tex]

Now, we have to calculate the value of P(x) at x = 1 and x = -2.

For this, we will substitute the value of x in the given polynomial and find it's value.

At x = 1;

[tex]\text{P}(1) = 2(1)^{5} +9(1)^{4} +9(1)^{3} +3(1)^{2}+7(1)-6[/tex]

[tex]\text{P}(1) = (2\times 1) +(9\times 1)+(9 \times 1)+(3\times 1)+(7\times 1)-6[/tex]

[tex]\text{P}(1) = 2 +9+9+3+7-6[/tex]

P(1) = 30 - 6

P(1) = 24

At x = -2;

[tex]\text{P}(-2) = 2(-2)^{5} +9(-2)^{4} +9(-2)^{3} +3(-2)^{2}+7(-2)-6[/tex]

[tex]\text{P}(-2) = (2\times -32) +(9\times 16)+(9 \times -8)+(3\times 4)+(7\times -2)-6[/tex]

[tex]\text{P}(-2) = -64 +144-72+12-14-6[/tex]

P(-2) = 156 - 156

P(-2) = 0

Hence, the value of the polynomial function at P(1) and P(-2) is 24 and 0 respectively.

The perimeter of a rectangular field is 344m . If the width of the field is 75m, what is its length?

Answers

Answer:

97 m

Step-by-step explanation:

Perimeter = 2 * (length + width); perimeter = 344, width = 75 (solving for length)

344 = 2(length + 75)

172 = length + 75

length = 97

solve for the inequality ᵏ⁄₄ ≥ 6

Answers

Answer:

k ≥ 24

Step-by-step explanation:

ᵏ⁄₄ ≥ 6

Multiply each side by 4

ᵏ⁄₄ *4 ≥ 6*4

k ≥ 24

Answer:

k≥24

Step-by-step explanation:

k/4≥6

Use the multiplication property of equality by multiplying both sides by 4 to get

k≥24

If this is wrong or if I did something wrong, please tell me so I can learn the proper way, I am just treating this like a normal problem

Thank you

The random variable x is the number of houses sold by a realtor in a single month at the Sendsom's Real Estate office. Its probability distribution is as follows:
Houses Sold (x) Probability P(x)
0 0.24
1 0.01
2 0.12
3 0.16
4 0.01
5 0.14
6 0.11
7 0.21
Find the mean of the given probability distribution.
A. μ = 3.35
B. μ = 3.50
C. μ = 3.60
D. μ = 3.40

Answers

Answer:

C. μ = 3.60

Step-by-step explanation:

Two tables have been attached to this response.

One of the tables contains the given data and distribution with two columns: Houses Sold and Probability

The other table contains the analysis of the data with additional columns: Frequency and Fx

=> The Frequency(F) column is derived from the product of the probability of each item in the Houses sold column and the total number of houses sold (which is 28). For example,

When the number of houses sold = 0

F = P(0) x Total number of houses sold

F = 0.24 x 28 = 6.72

When the number of houses sold = 1

F = P(1) x Total number of houses sold

F = 0.01 x 28 = 0.28

=> The Fx column is found by multiplying the Frequency column by the Houses Sold column. For example,

When the number of houses sold = 0

Fx = F * x

F = 6.72 x 0 = 0

Now to get the mean, μ we use the relation;

μ = ∑Fx / ∑F

Where;

∑Fx = summation of the items in the Fx column = 100.8

∑F = summation of the items in the Frequency column = 28

μ = 100.8 / 28

μ = 3.60

Therefore, the mean of the given probability distribution is 3.60

The mean of the discrete probability distribution is given by:

C. μ = 3.60

What is the mean of a discrete distribution?

The expected value of a discrete distribution is given by the sum of each outcome multiplied by it's respective probability.

In this problem, the table x - P(x) gives each outcome and their respective probabilities, hence, the mean is:

[tex]E(X) = 0(0.24) + 1(0.01) + 2(0.12) + 3(0.16) + 4(0.01) + 5(0.14) + 6(0.11) + 7(0.21) = 3.6[/tex]

Hence option C is correct.

More can be learned about the mean of discrete distributions at https://brainly.com/question/24855677

An article reports that when each football helmet in a random sample of 34 suspension-type helmets was subjected to a certain impact test, 24 showed damage. Let p denote the proportion of all helmets of this type that would show damage tested in the prescribed manner.

Required:
a. Calculate a 99% Cl for p.
b. What sample size would be required for the width of a 99% Cl to beat most .10, irrespective of p ?

Answers

Answer:

a

    [tex]0.5043 < p <0.9075[/tex]

b

   [tex]n = 24[/tex]

Step-by-step explanation:

From the question we are told that

    The sample size is  n =  34

    The  number of damaged helmets is  x  =  24

Now the proportion of damaged helmets is mathematically represented as

      [tex]\r p = \frac{k}{n }[/tex]

substituting values

     [tex]\r p = \frac{24}{34 }[/tex]

    [tex]\r p = 0.7059[/tex]

Given that the confidence level is 99% the level of significance can be evaluated as

     [tex]\alpha = 100 - 99[/tex]

     [tex]\alpha = 1[/tex]%

    [tex]\alpha = 0.01[/tex]

Next we obtain the critical value of  [tex]\frac{\alpha }{2}[/tex]  from the normal distribution table, the value is  [tex]Z_{\frac{\alpha }{2} } = 2.58[/tex]

The reason we are obtaining critical values of   [tex]\frac{\alpha }{2}[/tex] instead of   [tex]\alpha[/tex] is because  

[tex]\alpha[/tex] represents the area under the normal curve where the confidence level interval (  [tex]1-\alpha[/tex]) did not cover which include both the left and right tail while  

[tex]\frac{\alpha }{2}[/tex]is just the area of one tail which what we required to calculate the margin of error

   The margin of error is mathematically represented as

     [tex]MOE = Z_{\frac{\alpha }{2} } * \sqrt{\frac{\r p ( 1 - \r p)}{n} }[/tex]

substituting values

      [tex]MOE = 2.58 * \sqrt{\frac{ 0.7059 ( 1 - 0.7059)}{34} }[/tex]

     [tex]MOE =0.2016[/tex]

The 99% confidence interval for p is mathematically represented as

      [tex]p-MOE < p < p + MOE[/tex]

substituting values

       [tex]0.7059 - 0.2016 < p <0.7059 + 0.2016[/tex]

      [tex]0.5043 < p <0.9075[/tex]

The  sample size required for the width of a 99% Cl to beat most 0.10, irrespective of p ? is mathematically represented as  

     [tex]n \ge \frac{ Z_{\frac{\alpha }{2} } * \sqrt{\r p (1- \r p )} }{\frac{\sigma }{2} }[/tex]

Here  [tex]\sigma = 0.10[/tex]  telling  us that the deviation from the sample proportion is  set to 0.10 irrespective of the value of  [tex]\r p[/tex]

so the  sample size for this condition is

    [tex]n \ge \frac{ 2.58 * \sqrt{ 0.7059 (1- 0.7059)} }{\frac{0.10 }{2} }[/tex]

    [tex]n \ge 23.51[/tex]

=>   [tex]n = 24[/tex]

Does it take more large paper clips or small paper cps lined up end to end to measure the
width of a piece of printer paper? Explain.

Answers

Answer:

Step-by-step explanation:

You haven't answered any questions, yet…

The circumference of C is 72cm. What is the length of AB (the minor arc)

Answers

Answer:

Step-by-step explanation:

Can you please include a image?

Thanks!!!

Find the volume of the figure below. Round to the nearest tenth.
7 cm
7 cm
9 cm
20 cm
11 cm

Answers

Answer:

3057.6 cm³

Step-by-step explanation:

You have a cylinder and a rectangular prism.  Solve for the area of each separately.

Cylinder

The formula for volume of a cylinder is V = πr²h.  The radius is 7, and the height is 7.

V = πr²h

V = π(7)²(7)

V = π(49)(7)

V = 343π

V = 1077.57 cm³

Rectangular Prism

The formula for volume of a rectangular prism is V = lwh.  The length is 20, the width is 11, and the height is 9.

V = lwh

V = (20)(11)(9)

V = (220)(9)

V = 1980 cm³

Add the areas of the two shapes.

1077.57 cm³ + 1980 cm³ = 3057.57 cm³

Round to the nearest tenth.

3057.57 cm³ ≈ 3057.6 cm³

Find the slope of the line passing through the points (-5, 3) and (7,9).

Answers

Answer:

[tex]\huge\boxed{slope=\dfrac{1}{2}=0.5}[/tex]

Step-by-step explanation:

The formula of a slope:

[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]

We have the points

[tex](-5;\ 3)\to x_1=-5;\ y_1=3\\(7;\ 9)\to x_2=7;\ y_2=9[/tex]

Substitute:

[tex]m=\dfrac{9-3}{7-(-5)}=\dfrac{6}{7+5}=\dfrac{6}{12}=\dfrac{6:6}{12:6}=\dfrac{1}{2}[/tex]

Answer:

1/2

Step-by-step explanation:

We can use the slope formula since we have 2 points

m = ( y2-y1)/(x2-x1)

    = (9-3)/( 7 - -5)

    = (9-3) /( 7+5)

   = 6/ 12

  = 1/2

What is the range of the function f(x)=3/4|x|-3

Answers

Range is [tex]y\in[-3,+\infty)[/tex].

Hope this helps.

how many solutions does this linear system hacve y=2/3x+2 6x-4y=-10

Answers

Answer:

the linear system has two valid solution.

Answer:one solution

Step-by-step explanation:

Evaluate the following geometric sum.
1/2 + 1/10 + ( 1/50) + (1/250 ) + midline ellipsis + (1/31,250)

Answers

Answer:

39062/62,500

Step-by-step explanation:

Given the following geometric progression; 1/2 + 1/10 + ( 1/50) + (1/250 ) + ... + (1/31,250),the sum of the arithmetic geometric progression is expressed using the formula below;

Sn = a(1-rⁿ)/1-r  for r less than 1

r is the common ratio

n is the number of terms

a is the first term of the series

In between the mid-line ellipsis there are 2 more terms, making the total number of terms n to be 7]

common ratio = (1/10)/(1/2) =  (1/50)/(1/10) =  (1/250)/(1/50) = 1/5  

a = 1/2

Substituting the given values into the equation above

S7 = 1/2{1 - (1/5)⁷}/1 - 1/5

S7 = 1/2(1- 1/78125)/(4/5)

S7 = 1/2 (78124/78125)/(4/5)

S7 = 78124/156,250 * 5/4

S7 = 390,620/625000

S7 = 39062/62,500

Hence the geometric sum is 39062/62,500

What are the explicit equation and domain for a geometric sequence with a first term of 2 and a second term of −8?

Answers

Step-by-step explanation:

the common ratio is -4

Gn=2 (-4)^n-1

In a survey, 29 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $41 and standard deviation of $8. Construct a confidence interval at a 99% confidence level.
Give your answers to one decimal place.

Answers

Answer:

The  99%  confidence interval is

                     [tex]37.167< \= x < 44.833[/tex]

Step-by-step explanation:

From the question we are told that

  The sample size is  [tex]n = 29[/tex]

  The  sample mean is  [tex]\= x =[/tex]$41

  The  sample standard deviation is  [tex]\sigma =[/tex]$8

   The  level of confidence is [tex]C =[/tex]99%

Given that the confidence level id  99% the level of confidence is evaluated as

        [tex]\alpha = 100 - 99[/tex]

        [tex]\alpha = 1[/tex]%

Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table which is  

      [tex]Z_{\frac{\alpha }{2} } = 2.58[/tex]

The reason we are obtaining values for  is because  is the area under the normal distribution curve for both the left and right tail where the 99% interval did not cover while   is the area under the normal distribution curve for just one tail and we need the  value for one tail in order to calculate the confidence interval

Next we evaluate the margin of error which is mathematically represented as

          [tex]MOE = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]

substituting values

         [tex]MOE = 2.58 * \frac{8 }{\sqrt{29} }[/tex]

           [tex]MOE = 3.8328[/tex]

The 99% confidence level is constructed as follows

      [tex]\= x - MOE < \= x < \= x + MOE[/tex]

substituting values

    [tex]41 - 3.8328 < \= x < 41 + 3.8328[/tex]

     [tex]37.167< \= x < 44.833[/tex]

6th grade math , help me please:)

Answers

Answer:

(a) $7/ticket

(b) 3 cats/dog

(c) 10 ft/sec

(d) 16 cups/gal

Step-by-step explanation:

(a) $35 for 5 tickets

$35/(5 tickets) = $7/ticket

(b) 21 cats and 7 dogs

21 cats/(7 dogs) = 3 cats/dog

(c) 40 ft in 4 seconds

40 ft/(4 sec) = 10 ft/sec

(d) 48 cups for 3 gallons

48 cups/(3 gal) = 16 cups/gal

Solve the initial value problem y′+y=f(t),y(0)=0 where f(t)={1,−1, if t<4 if t≥4 Use h(t−a) for the Heaviside function shifted a units horizontally.

Answers

Looks like the function on the right hand side is

[tex]f(t)=\begin{cases}1&\text{for }t<4\\-1&\text{for }t\ge4\end{cases}[/tex]

We can write it in terms of the Heaviside function,

[tex]h(t-a)=\begin{cases}1&\text{for }t\ge a\\0&\text{for }t>a\end{cases}[/tex]

as

[tex]f(t)=h(t)-2h(t-4)[/tex]

Now for the ODE: take the Laplace transform of both sides:

[tex]y'(t)+y(t)=f(t)[/tex]

[tex]\implies s Y(s)-y(0)+Y(s)=\dfrac{1-2e^{-4s}}s[/tex]

Solve for Y(s), then take the inverse transform to solve for y(t):

[tex](s+1)Y(s)=\dfrac{1-e^{-4s}}s[/tex]

[tex]Y(s)=\dfrac{1-e^{-4s}}{s(s+1)}[/tex]

[tex]Y(s)=(1-e^{-4s})\left(\dfrac1s-\dfrac1{s+1}\right)[/tex]

[tex]Y(s)=\dfrac1s-\dfrac{e^{-4s}}s-\dfrac1{s+1}+\dfrac{e^{-4s}}{s+1}[/tex]

[tex]\implies y(t)=1-h(t-4)-e^{-t}+e^{-(t-4)}h(t-4)[/tex]

[tex]\boxed{y(t)=1-e^{-t}-h(t-4)(1-e^{-(t-4)})}[/tex]

Please answer in the form of a number

Answers

Answer:

d ≈ 8.3

Step-by-step explanation:

This is kind of like the pythagorean theorem, but with one extra value.  Thus, [tex]d^2=l^2+w^2+h^2[/tex].

Plug in the values to get:

[tex]d^2=2^2+7^2+4^2\\d^2=4+49+16\\d^2=69\\d=\sqrt{69} \\[/tex]

Thus d ≈ 8.3

A potato chip company makes potato chips in two flavors, Regular and Salt & Vinegar. Riley is a production manager for the company who is trying to ensure that each bag contains about the same number of chips, regardless of flavor. He collects two random samples of 10 bags of chips of each flavor and counts the number of chips in each bag. Assume that the population variances of the number of chips per bag for both flavors are equal and that the number of chips per bag for both flavors are normally distributed. Let the Regular chips be the first sample, and let the Salt & Vinegar chips be the second sample. Riley conducts a two-mean hypothesis test at the 0.05 level of significance, to test if there is evidence that both flavors have the same number of chips in each bag. (a) H0:μ1=μ2; Ha:μ1≠μ2, which is a two-tailed test. (b) t≈1.44 , p-value is approximately 0.167 (c) Which of the following are appropriate conclusions for this hypothesis test? Select all that apply. Select all that apply:

Answers

Answer:

(a) H0:μ1=μ2; Ha:μ1≠μ2, which is a two-tailed test.

Step-by-step explanation:

We formulate the

H0: μ1=μ2; null hypothesis that the two means are equal and alternate hypothesis that the two mean are not equal.

Ha:μ1≠μ2 Two tailed test

Test statistic used is

t= x1`-x2` / s√n as the variances are equal and sample size is same

T value for 9 degrees of freedom for two tailed test at α = 0.05 is 2.26

P- value for t test for 9 degrees of freedom is 0.125 from the table.

Hence only a is correct .

Solve the following rational equation for x.
1/4x-3/4=7/x

Answers

Answer:

x1= -4, x2 = 7

Step-by-step explanation:

Move expression to the left-hand side:

1/4x-3/4-7/x=0

Write all the numerators above a common denominator:

x^2 - 3x - 28 /4x =0

When the quotient of expressions equal 0, the numerator has to be 0

x^2 + 4x - 7x - 28 = 0

x(x+4) - 7(x+4) =0

(x+4) × (x-7) =0

Separate into possible cases:

x+4=0

x-7=0

Answer: -9

Step-by-step explanation:

Given: AD = BC and AD || BC
Prove: ABCD is a parallelogram.
Angles Segments Triangles Statements Reasons
ZBCA
DAC
A
Statements
Reasons
00
D
с
Assemble the proof by dragging tiles to
the Statements and Reasons columns.

Answers

Do you have the picture to the problem ?

Triangle DAC is congruent to triangle BCA by SAS congruence theorem.

What is the congruence theorem?

Triangle congruence theorem or triangle congruence criteria help in proving if a triangle is congruent or not. The word congruent means exactly equal in shape and size no matter if we turn it, flip it or rotate it.

Given that, AD = BC and AD || BC.

AD = BC (Given)

AD || BC (Given)

AC = AC (Reflexive property)

∠DAC=∠BCA (Interior alternate angles)

By SAS congruence theorem, ΔDAC≅ΔBCA

By CPCT, AB=CD

Therefore, triangle DAC is congruent to triangle BCA by SAS congruence theorem.

To learn more about the congruent theorem visit:

https://brainly.com/question/24033497.

#SPJ5

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