Find the area of the shaded region. The graph to the right depicts IQ scores of adults, and those scores are normally distributed with a
mean of 100 and a standard deviation of 15.
n
f0 and
102
130
are
The area of the shaded region is (Round to four decimal places as needed.)
sions
Kented in
V3 and
andomly
d by in-
on affect
otes
ents
le
Enter your answer in the answer box and then click Check Answer.
section
different
version
Clear All
Check Answer
All parts showing
Answers
Answer: 0.4255
Step-by-step explanation:
Given: IQ scores of adults, and those scores are normally distributed
Mean: [tex]\mu=100[/tex]
Standard deviation: [tex]\sigma= 15[/tex]
Let X denotes the IQ of a random adults.
The area between 102 and 130 = [tex]P(102<X<130)=P(\dfrac{102-100}{15}<\dfrac{X-\mu}{\sigma}<\dfrac{130-100}{15})[/tex]
[tex]=P(0.13<Z<2)\ \ \ [Z=\dfrac{X-\mu}{\sigma}]\\\\=P(Z<2)-P(Z<0.13)\\\\=0.9772- 0.5517\ [\text{By z-table}]\\\\=0.4255[/tex]
Hence, area between 102 and 130 = 0.4255
Related Questions
Test the claim that the proportion of men who own cats is smaller than 70% at the 0.05 significance level. The null and alternative hypothesis would be:
Answers
Answer:
the null hypothesis would be: p = 70%/0.7
The alternative hypothesis would be: p < 0.7
Step-by-step explanation:
The null hypothesis is most of the time always the default statement while the alternative hypothesis is tested against the null and is its opposite.
In this case study the null hypothesis would be: the proportion of men who own cats is 70%: p = 0.7
The alternative hypothesis would be: the proportion of men who own cats is smaller than 70% : p < 0.7
Find the exact values of sin 2θ and cos 2θ for cos θ = 6/13
Answers
Answer:
Step-by-step explanation:
cos^-1(6/13)=62.5136°
sin(2*62.5136°)=0.8189
cos(2*62.5136°)=-0.5740
What is the exact volume of the cylinder? Enter your answer, in terms of π, in the box. m³ $\text{Basic}$ $x$$y$$x^2$$\sqrt{ }$$\frac{x}{ }$ $x\frac{ }{ }$ $x^{ }$$x_{ }$$\degree$$\left(\right)$$\abs{ }$$\pi$$\infty$ A cylinder that is 2.5 m tall with a radius of 1.5 m
Answers
Answer:
[tex]5.625\pi[/tex] m³.
Step-by-step explanation:
The volume of a cylinder is found by calculating pi * r^2 * h.
In this case, h = 2.5, and r = 1.5.
pi * 1.5^2 * 2.5
= pi * 2.25 * 2.5
= pi * 5.625
So, the exact volume of the cylinder is [tex]5.625\pi[/tex] m³.
Hope this helps!
Answer: Volume of Cylinder: [tex]\pi r^{2} *h[/tex]
5.625π m.
Step-by-step explanation:
[tex]\pi r^{2} *h[/tex] Cylinder Area Formula
[tex]\pi *1.5^{2} *2.5[/tex] Substitution
[tex]\pi * 2.25 *2.5[/tex] Exponent
[tex]\pi *5.625[/tex] Multiply
[tex]5.625\pi[/tex] Answer
You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 60%. You would like to be 98% confident that your estimate is within 2.5% of the true population proportion. How large of a sample size is required?
Answers
Answer:
A sample size of 2080 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
98% confidence level
So [tex]\alpha = 0.02[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.02}{2} = 0.99[/tex], so [tex]Z = 2.327[/tex].
Based on previous evidence, you believe the population proportion is approximately 60%.
This means that [tex]\pi = 0.6[/tex]
How large of a sample size is required?
We need a sample of n.
n is found when [tex]M = 0.025[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.025 = 2.327\sqrt{\frac{0.6*0.4}{n}}[/tex]
[tex]0.025\sqrt{n} = 2.327\sqrt{0.6*0.4}[/tex]
[tex]\sqrt{n} = \frac{2.327\sqrt{0.6*0.4}}{0.025}[/tex]
[tex](\sqrt{n})^{2} = (\frac{2.327\sqrt{0.6*0.4}}{0.025})^{2}[/tex]
[tex]n = 2079.3[/tex]
Rounding up
A sample size of 2080 is needed.
Betty and Karen have been hired to paint the houses in a new development. Working together, the women can paint a house in two-thirds the time that it takes Karen working alone. Betty takes 14 h to paint a house alone. Betty takes 6 h to paint a house alone.
Required:
How long does it take Karen to paint a house working alone?
Answers
Answer: 3 hours
Step-by-step explanation:
Here is the correct question:
Betty and karen have been hired to paint the houses in a new development. Working together the women can paint a house in two thirds the time that it takes karen working alone. Betty takes 6 hours to paint a house alone. How long does it take karen to paint a house working alone?
Since Betty takes 6 hours to paint a house alone, that means she can paint 1/6 of the house in 1 hour.
Karen can also paint 1/x in 1 hour
Both of them will paint the house in 3/2 hours.
We then add them together which gives:
1/6 + 1/x = 3/2x
The lowest common multiple is 6x
1x/6x + 6/6x = 9/6x
We then leave out the denominators
1x + 6 = 9
x = 9 - 6
x = 3
Karen working alone will paint a house in 3 hours.
Which number line represents the solution set for the inequality 3(8 - 4x) < 6(x - 5)?
Answers
Answer:
x>3
Step-by-step explanation:
g Find the mean and the variance of the random variable X with probability function or density f(x) of a uniform distribution on [0, 8].
Answers
Answer: E(X) = 4
V(X) = [tex]\frac{16}{3}[/tex]
Step-by-step explanation: An uniform distribution is a random variable X restricted to a finite interval [a,b] and has a constant function f(x) over this interval, i.e., the function is of form:
f(x) = [tex]\left \{ {{\frac{1}{b-a} } \atop {0}} \right.[/tex]
The mean or expectation of an unifrom distribution is:
E(X) = [tex]\int\limits^b_a {x.f(x)} \, dx[/tex]
For the density function in interval [0,8], expectation value is:
E(X) = [tex]\int\limits^8_0 {x.(\frac{1}{8-0} )} \, dx[/tex]
E(X) = [tex]\int\limits^8_0 {\frac{x}{8} } \, dx[/tex]
E(X) = [tex]\frac{1}{8}. \int\limits^8_0 {x} \, dx[/tex]
E(X) = [tex]\frac{1}{8}.(\frac{x^{2}}{2} )[/tex]
E(X) = [tex]\frac{1}{8} (\frac{8^{2}}{2} )[/tex]
E(X) = 4
Variance of a probability distribution can be written as:
V(X) = [tex]E(X^{2}) - [E(X)]^{2}[/tex]
For uniform distribution in interval [0,8]:
V(X) = [tex]\int\limits^b_a {x^{2}.\frac{1}{8-0} } \, dx - (\frac{8+0}{2})^{2}[/tex]
V(X) = [tex]\frac{1}{8} \int\limits^8_0 {x^{2}} \, dx - 4^{2}[/tex]
V(X) = [tex]\frac{1}{8} (\frac{x^{3}}{3} ) - 16[/tex]
V(X) = [tex]\frac{1}{8} (\frac{8^{3}}{3} ) - 16[/tex]
V(X) = [tex]\frac{64}{3}[/tex] - 16
V(X) = [tex]\frac{16}{3}[/tex]
The mean and variance are 4 and 16/3, respectively
Please answer this correctly without making mistakes
Answers
Answer:
41.1 miles
Step-by-step explanation:
84 - 42.9 = 41.1
When doing blood testing for a viral infection, the procedure can be made more efficient and less expensive by combining partial samples of different blood specimens. If samples from five people are combined and the mixture tests negative, we know that all five individual samples are negative. Find the probability of a positive result for five samples combined into one mixture, assuming the probability of an individual blood sample testing positive for the virus is 0.06.
Answers
Answer: 0.271
Step-by-step explanation:
Probability of complement of an even is 1 decreased by the probability of the event
P(At least one) =1 - P(none)
The probability that of testing negative is 0.9 because the probability of testing positive is 0.1
P( at least one) = 1 - P(none) = 1 - (0.93^3) = 0.271
x−15≤−6 solve for x pls help
Answers
Answer:
x≤9
Step-by-step explanation:
x−15≤−6
Add 15 to each side
x−15+15≤−6+15
x≤9
Answer:
[tex]\boxed{x\leq 9}[/tex]
Step-by-step explanation:
[tex]x-15 \leq -6[/tex]
[tex]\sf Add \ 15 \ to \ both \ parts.[/tex]
[tex]x-15 +15 \leq -6+15[/tex]
[tex]x\leq 9[/tex]
6th grade math help me, please :))
Answers
Answer:
D
Step-by-step explanation:
100/5=20
20*7=140
The radius of a nitrogen atom is 5.6 × 10-11 meters, and the radius of a beryllium atom is 1.12 × 10-10 meters. Which atom has a larger radius, and by how many times is it larger than the other?
Answers
Answer:
The beryllium atom; 1.99 times larger.
Step-by-step explanation:
The beryllium atom is 0.000000000112 meters, while the nitrogen atom is 0.000000000056 meters. So, the beryllium atom is larger than the other.
(1.12 * 10^-10) / (5.6 * 10^-11)
= (1.112 / 5.6) * (10^-10 + 11)
= 0.1985714286 * 10
= 1.985714286 * 10^0
So, the beryllium atom is about 1.99 times larger than the other.
Hope this helps!
What is the equation for the plane illustrated below?
Answers
Answer:
Hence, none of the options presented are valid. The plane is represented by [tex]3 \cdot x + 3\cdot y + 2\cdot z = 6[/tex].
Step-by-step explanation:
The general equation in rectangular form for a 3-dimension plane is represented by:
[tex]a\cdot x + b\cdot y + c\cdot z = d[/tex]
Where:
[tex]x[/tex], [tex]y[/tex], [tex]z[/tex] - Orthogonal inputs.
[tex]a[/tex], [tex]b[/tex], [tex]c[/tex], [tex]d[/tex] - Plane constants.
The plane presented in the figure contains the following three points: (2, 0, 0), (0, 2, 0), (0, 0, 3)
For the determination of the resultant equation, three equations of line in three distinct planes orthogonal to each other. That is, expressions for the xy, yz and xz-planes with the resource of the general equation of the line:
xy-plane (2, 0, 0) and (0, 2, 0)
[tex]y = m\cdot x + b[/tex]
[tex]m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
Where:
[tex]m[/tex] - Slope, dimensionless.
[tex]x_{1}[/tex], [tex]x_{2}[/tex] - Initial and final values for the independent variable, dimensionless.
[tex]y_{1}[/tex], [tex]y_{2}[/tex] - Initial and final values for the dependent variable, dimensionless.
[tex]b[/tex] - x-Intercept, dimensionless.
If [tex]x_{1} = 2[/tex], [tex]y_{1} = 0[/tex], [tex]x_{2} = 0[/tex] and [tex]y_{2} = 2[/tex], then:
Slope
[tex]m = \frac{2-0}{0-2}[/tex]
[tex]m = -1[/tex]
x-Intercept
[tex]b = y_{1} - m\cdot x_{1}[/tex]
[tex]b = 0 -(-1)\cdot (2)[/tex]
[tex]b = 2[/tex]
The equation of the line in the xy-plane is [tex]y = -x+2[/tex] or [tex]x + y = 2[/tex], which is equivalent to [tex]3\cdot x + 3\cdot y = 6[/tex].
yz-plane (0, 2, 0) and (0, 0, 3)
[tex]z = m\cdot y + b[/tex]
[tex]m = \frac{z_{2}-z_{1}}{y_{2}-y_{1}}[/tex]
Where:
[tex]m[/tex] - Slope, dimensionless.
[tex]y_{1}[/tex], [tex]y_{2}[/tex] - Initial and final values for the independent variable, dimensionless.
[tex]z_{1}[/tex], [tex]z_{2}[/tex] - Initial and final values for the dependent variable, dimensionless.
[tex]b[/tex] - y-Intercept, dimensionless.
If [tex]y_{1} = 2[/tex], [tex]z_{1} = 0[/tex], [tex]y_{2} = 0[/tex] and [tex]z_{2} = 3[/tex], then:
Slope
[tex]m = \frac{3-0}{0-2}[/tex]
[tex]m = -\frac{3}{2}[/tex]
y-Intercept
[tex]b = z_{1} - m\cdot y_{1}[/tex]
[tex]b = 0 -\left(-\frac{3}{2} \right)\cdot (2)[/tex]
[tex]b = 3[/tex]
The equation of the line in the yz-plane is [tex]z = -\frac{3}{2}\cdot y+3[/tex] or [tex]3\cdot y + 2\cdot z = 6[/tex].
xz-plane (2, 0, 0) and (0, 0, 3)
[tex]z = m\cdot x + b[/tex]
[tex]m = \frac{z_{2}-z_{1}}{x_{2}-x_{1}}[/tex]
Where:
[tex]m[/tex] - Slope, dimensionless.
[tex]x_{1}[/tex], [tex]x_{2}[/tex] - Initial and final values for the independent variable, dimensionless.
[tex]z_{1}[/tex], [tex]z_{2}[/tex] - Initial and final values for the dependent variable, dimensionless.
[tex]b[/tex] - z-Intercept, dimensionless.
If [tex]x_{1} = 2[/tex], [tex]z_{1} = 0[/tex], [tex]x_{2} = 0[/tex] and [tex]z_{2} = 3[/tex], then:
Slope
[tex]m = \frac{3-0}{0-2}[/tex]
[tex]m = -\frac{3}{2}[/tex]
x-Intercept
[tex]b = z_{1} - m\cdot x_{1}[/tex]
[tex]b = 0 -\left(-\frac{3}{2} \right)\cdot (2)[/tex]
[tex]b = 3[/tex]
The equation of the line in the xz-plane is [tex]z = -\frac{3}{2}\cdot x+3[/tex] or [tex]3\cdot x + 2\cdot z = 6[/tex]
After comparing each equation of the line to the definition of the equation of the plane, the following coefficients are obtained:
[tex]a = 3[/tex], [tex]b = 3[/tex], [tex]c = 2[/tex], [tex]d = 6[/tex]
Hence, none of the options presented are valid. The plane is represented by [tex]3 \cdot x + 3\cdot y + 2\cdot z = 6[/tex].
Answer:
It is A 3x+3y+2z=6
Step-by-step explanation:
E={a,c,f}
A={a,c,j}
find the intersection of E and A.
find the union of E and A
write your answer using set notation (in roster form)
Answers
Answer:
i. E ∩ A = { a , c }ii. E ∪ A = { a , c , f , j }Step-by-step explanation:
Given
E = { a , c , f }
A = { a , c , j }
i) Let's find the intersection of E and A
E ∩ A = { a , c , f } ∩ { a , c , j }
In the case of intersection , we have to list the elements which are common in both sets:
E ∩ A = { a , c }
ii) Let's find the union of E and A
E ∪ A = ( a , c , f } { a , c , j }
In the case of Union, we have to list all the elements which are present in both sets.
E ∪ A = { a , c , f , j }
Hope this helps..
Best regards!!
? Question
A slingshot launches a water balloon into the air. Function f models the height of the balloon, where x is the horizontal
distance in feet:
f(x) = -0.05x2 +0.8x + 4.
From what height did the slingshot launch the balloon, and what was the balloon's maximum height? How far from the
slingshot did the balloon land?
The balloon's maximum height was____
The slingshot
launched the balloon from a height of _____
The balloon landed_____
from the slingshot.
Answers
Answer:
4 ft
7.2 ft
20 ft
Step-by-step explanation:
When the balloon is shot, x = 0.
y = -0.05(0)² + 0.8(0) + 4
y = 4
The balloon reaches the highest point at the vertex of the parabola.
x = -b / 2a
x = -0.8 / (2 × -0.05)
x = 8
y = -0.05(8)² + 0.8(8) + 4
y = 7.2
When the balloon lands, y = 0.
0 = -0.05x² + 0.8x + 4
0 = x² − 16x − 80
0 = (x + 4) (x − 20)
x = -4 or 20
Since x > 0, x = 20.
The slingshot launched the ballon from a height of 4 feet. The balloon's maximum height was 72 feet. The balloon landed 20 feet from the slingshot.
To determine the height from which the slingshot launched the balloon, we need to evaluate the function f(0) because when x is zero, it represents the starting point of the balloon's trajectory.
f(x) = -0.05x² + 0.8x + 4
f(0) = -0.05(0)² + 0.8(0) + 4
f(0) = 4
Therefore, the slingshot launched the balloon from a height of 4 feet.
To find the maximum height of the balloon, we can observe that the maximum point of the parabolic function occurs at the vertex.
The x-coordinate of the vertex can be calculated using the formula x = -b / (2a).
In our case, a = -0.05 and b = 0.8.
Let's calculate the x-coordinate of the vertex:
x = -0.8 / (2×(-0.05))
x = -0.8 / (-0.1)
x = 8
Now, substitute this x-coordinate into the function to find the maximum height:
f(x) = -0.05x² + 0.8x + 4
f(8) = -0.05(8)² + 0.8(8) + 4
f(8) = -0.05(64) + 6.4 + 4
f(8) = -3.2 + 6.4 + 4
f(8) = 7.2
Therefore, the balloon reached a maximum height of 7.2 feet.
To determine how far from the slingshot the balloon landed, we need to find the x-intercepts of the quadratic function.
These represent the points where the height is zero, indicating the balloon has landed.
Setting f(x) = 0, we can solve the quadratic equation:
-0.05x² + 0.8x + 4 = 0
x² - 16x - 80= 0
x=-4 or x=20
We take the positive value, so the balloon landed 20 feet from the slingshot.
To learn more on Quadratic equation click:
https://brainly.com/question/17177510
#SPJ2
Which of the following graphs is described by the function below ?
Answers
Answer:
The point of interception of the graph and x axis are -2.366 and -0.634.
The only graph that satisfy this conditions is Graph A
Step-by-step explanation:
Given the equation;
[tex]y = 2x^2 + 6x + 3\\[/tex]
at y = 0
[tex]2x^2 + 6x + 3=0\\[/tex]
the roots of the quadratic equation (at y =0) can be calculated using the quadratic formula;
[tex]x = \frac{-b\pm \sqrt{b^2 -4ac}}{2a}[/tex]
Using the quadratic equation to solve for the roots;
[tex]x = \frac{-6\pm \sqrt{6^2 -4*2*3}}{2*2}\\x = \frac{-6\pm \sqrt{36 - 24}}{4}\\x = \frac{-6\pm \sqrt{12}}{4}\\so, we have \\x = -2.366\\or\\x = -0.634\\[/tex]
Therefore, the point of interception of the graph and x axis are -2.366 and -0.634.
The only graph that satisfy this conditions is Graph A
the product of two consequtive integers is 72 the equation x(x+1)=72 represents the situation, where x represents the smaller integer, which equation can be factor and solve for the smaller integer?
Answers
Answer:
x² + x - 72 = 0 can be factored into (x - 8)(x + 9) = 0 to find your answer.
Step-by-step explanation:
Step 1: Distribute x
x² + x = 72
Step 2: Move 72 over
x² + x - 72 = 0
Step 3: Factor
(x - 8)(x + 9) = 0
Step 4: Find roots
x - 8 = 0
x = 8
x + 9 = 0
x = -9
Answer:
x² + x - 72 = 0 ⇒ (x - 8)(x + 9) = 0
Step-by-step explanation:
Let the first consecutive integer be x.
Let the second consecutive integer be x+1.
The product of the two consecutive integers is 72.
x(x + 1) = 72
x² + x = 72
Subtracting 72 from both sides.
x² + x - 72 = 0
Factor left side of the equation.
(x - 8)(x + 9) = 0
Set factors equal to 0.
x - 8 = 0
x = 8
x + 9 = 0
x = -9
8 and -9 are not consecutive integers.
Try 8 and 9 to check.
x = 8
x + 1 = 9
x(x+1) = 72
8(9) = 72
72 = 72
True!
The two consecutive integers are 8 and 9.
Find the area under the standard normal curve to the right of z = 2.
Answers
Answer:
0.0228
Step-by-step explanation:
A suitable probability calculator (or spreadsheet) can tell you this.
It is about 0.0228.
The length of a rectangle is four times its width. If the perimeter of the rectangle is 50 yd, find its area
Answers
Answer:
100yd²
Step-by-step explanation:
length=4x
width=x
perimeter=2(l+w)
50=2(4x+x)
50=2(5x)=10x
50=10x
x=5yd
width=5yd
length=20yd
area=length×width
=20×5
=100yd²
Answer:
[tex]\boxed{\red{100 \: \: {yd} ^{2}}} [/tex]
Step-by-step explanation:
width = x
length = 4x
so,
perimeter of a rectangle
[tex] p= 2(l + w) \\ 50yd = 2(4x + x) \\ 50yd= 2(5x) \\ 50yd= 10x \\ \frac{50yd}{10} = \frac{10x}{10} \\ x = 5 \: \: yd[/tex]
So, in this rectangle,
width = 5 yd
length = 4x
= 4*5
= 20yd
Now, let's find the area of this rectangle
[tex]area = l \times w \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 20 \times 5 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 100 {yd}^{2} [/tex]
As the Type II error, β,of a statistical test increases, the power of the test _____________.
Answers
Answer:
decreases.
Step-by-step explanation:
Type II error is one in which we fail to reject the null hypothesis that is actually false. Null hypothesis is a statement that is to be tested against the alternative hypothesis and then decision is taken whether to accept or reject the null hypothesis. The power of Type II error is 1 - [tex]\beta[/tex]. As the power increases the probability of Type II error decreases.
I made a square frame for my favorite bird picture from four wooden pieces. Each piece is a rectangle with a perimeter of 24 inches. What is the area and perimeter of the picture and frame, together?
Answers
Answer:
Perimeter of the picture and frame = 38.4inches
Area of the picture and frame = 92.16inches²
Step-by-step explanation:
A square frame is made up of 4 different pieces. The shape of each piece = Rectangle
The perimeter of the rectangle = 24
Perimeter of the rectangle = 24 inches
The perimeter of a rectangle = 2L + 2W
The Width of a Rectangle is always on her than the length hence.
24 = 2L + 2W
24 = 2( L + W)
24/2 = L + W
12 = L + W
Because the width is always longer than the length
W > L
Width of wooden frame = 4 × Length
Therefore;
4 × L = W
Which gives
L + W = 12 inches
4 × L + L = 12 inches
L×(4 + 1)
= 5L = 12 inches
L = 12/5 = 2.4 inches
W = 4 × L = 4 × 12/5
W = 48/5 = 9.6 inches
Side length of wooden frame, L =9.6
The perimeter of the picture frame = 4 × L= 4 × 9.6= 38.4 inches
The area of the picture frame = L²
= L × L
= 9.6 × 9.6 = 92.16inches².
The value of y varies inversely as the square of x, and y = 16, when I = 3.
Find the value of x when y = 1.
Answers
Answer:
x = 12Step-by-step explanation:
The statement
The value of y varies inversely as the square of x is written as
[tex]y = \frac{k}{ {x}^{2} } [/tex]
where k is the constant of proportionality
To find the value of x when y = 1 first find the formula for the variation
y = 16 x = 3
k = yx²
k = 16(3)²
k = 16 × 9
k = 144
The formula for the variation is
[tex]y = \frac{144}{ {x}^{2} } [/tex]
when y = 1
We have
[tex]1 = \frac{144}{ {x}^{2} } [/tex]
Cross multiply
x² = 144
Find the square root of both sides
We have the final answer as
x = 12Hope this helps you
Six human skulls from around 4000 b.c. were measured, and the lengths have a mean of 94.2 mm and a standard deviation of 4.9
mm. If you want to construct a 95% confidence interval estimate of the mean length of all such skulls, assume that the requirements
are satisfied. Find the critical values that would be used to construct a 95% confidence interval estimate of o
Answers
Answer:
Step-by-step explanation:
Hello!
You have to estimate the mean length of 4000 b.c. human skulls trough a 95% confidence interval.
You know that
n= 6 human skulls
[tex]\frac{}{X}[/tex]= 94.2mm
S= 4.9
Assuming that the variable X: length of a 4000b.c. human skull (mm) has a normal distribution, to construct the interval you have to use the t statistic:
[[tex]\frac{}{X}[/tex] ± [tex]t_{n_1;1-\alpha /2} * \frac{S}{\sqrt{n} }[/tex]]
[tex]t_{n-1;1-\alpha /2}= t_{5; 0.975}= 2.571[/tex]
[94.2 ± 2.571 * [tex]\frac{4.9}{\sqrt{6} }[/tex]]
[89.06; 99.34]mm
With a 95% confidence level you'd expect the interval [89.06; 99.34]mm to contain the value for the average skull length for humans 4000 b.c.
I hope this helps!
Find the total surface area of the cone in the figure. ( use rr=3.14.)
Answers
Answer:
Answer D
Step-by-step explanation:
The formula is [tex]A = pi r(r+\sqrt{h^2+r^2})[/tex]. We have our r (radius) and h (height), so plugging it all in would give us A = (3.14)(5 + sqrt(12^2)+(5^2). After computing this, you would get answer D, 282.6.
Algebra 2, I need help!!! Solve x^2 + 6x + 7 = 0. If you are going to comment in here please know the answer, this is so serious for me. Thank you.
Answers
Answer:
Third option
Step-by-step explanation:
We can't factor this so we need to use the quadratic formula which states that when ax² + bx + c = 0, x = (-b ± √(b² - 4ac)) / 2a. However, we notice that b (which is 6) is even, so we can use the special quadratic formula which states that when ax² + bx + c = 0 and b is even, x = (-b' ± √(b'² - ac)) / a where b' = b / 2. In this case, a = 1, b' = 3 and c = 7 so:
x = (-3 ± √(3² - 1 * 7)) / 1 = -3 ± √2
What is the solution for x in the given equation? (root)9x+7+ (root)2x=7 A. x = 18 and x = 2 B. x = 18 C. x = 2 D. x = 18 and x = -2
Answers
Answer:
C. x = 2
Step-by-step explanation:
[tex] \sqrt{9x + 7} + \sqrt{2x} = 7 [/tex]
Since you have square roots, you need to separate the square roots and square both sides.
[tex] \sqrt{9x + 7} = 7 - \sqrt{2x} [/tex]
Now that one square root is on each side of the equal sign, we square both sides.
[tex] (\sqrt{9x + 7})^2 = (7 - \sqrt{2x})^2 [/tex]
[tex] 9x + 7 = 49 - 14\sqrt{2x} + 2x [/tex]
Now we isolate the square root and square both sides again.
[tex] 7x - 42 = -14\sqrt{2x} [/tex]
Every coefficient is a multiple of 7, so to work with smaller numbers, we divide both sides by 7.
[tex] x - 6 = -2\sqrt{2x} [/tex]
Square both sides.
[tex] (x - 6)^2 = (-2\sqrt{2x})^2 [/tex]
[tex] x^2 - 12x + 36 = 4(2x) [/tex]
[tex] x^2 - 20x + 36 = 0 [/tex]
We need to try to factor the left side.
-2 * (-18) = 36 & -2 + (-18) = -20, so we use -2 and -18.
[tex] (x - 2)(x - 18) = 0 [/tex]
[tex] x = 2 [/tex] or [tex] x = 18 [/tex]
Since solving this equation involved the method of squaring both sides, we much check for extraneous solutions by testing our two solutions in the original equation.
Test x = 2:
[tex] \sqrt{9x + 7} + \sqrt{2x} = 7 [/tex]
[tex] \sqrt{9(2) + 7} + \sqrt{2(2)} = 7 [/tex]
[tex] \sqrt{25} + \sqrt{4} = 7 [/tex]
[tex] 5 + 2 = 7 [/tex]
[tex] 5 = 5 [/tex]
We have a true equation, so x = 2 is a true solution of the original equation.
Now we test x = 18.
[tex] \sqrt{9x + 7} + \sqrt{2x} = 7 [/tex]
[tex] \sqrt{9(18) + 7} + \sqrt{2(18)} = 7 [/tex]
[tex] \sqrt{162 + 7} + \sqrt{36} = 7 [/tex]
[tex] \sqrt{169} + 6 = 7 [/tex]
[tex] 13 + 6 = 7 [/tex]
[tex] 19 = 7 [/tex]
Since 19 = 7 is a false equation, x = 18 is not a true solution of the original equation and is discarded as an extraneous solution.
Answer: C. x = 2
A line passes through the points (6, 10) and (4, -2). What is the equation of the line
Answers
Answer:
y = 6x - 26
Step-by-step explanation:
1. find slope: (y₂ - y₁) / (x₂ - x₁)
(-2 - 10) / (4 - 6) = -12 / -2 = 6
basic equation: y = 6x + b
2. plug in (x,y) value using one set of coordinates.
10 = 6(6) + b
10 = 36 + b
b = 10 - 36
b = -26
3. plug b in to find full equation.
y = 6x -26
Answer:
y = -1/6 x + 11
Step-by-step explanation:
In order to write an equation of a line you need slope (m) and y-intercept (b) or where the graph grosses the y- axis. since you are given two points (6, 10) and (4, -2). Slope when given two points is (y - y) / (x - x)
so (-2 - 10) / (6 - 4) = 6 / - 1 =- 6
use the equation y = mx + b and substitute either point (6, 10) or (4, -2) as a replacement for x and y respectively. (I chose (6, 10) because they are positive numbers. Substituting x = 6 and y = 10 and m = -6 into y = mx + b
10 = -6(6) + b
10 = -36 + b
b = 46 (add -36 to both sides)
so our equation: y = -6x + 46 :-)
Which steps can be used in order to determine the solution to Negative 1.3 + 4.6 x = 0.3 + 4 x?
Answers
Answer:
x=8/3 OR 2.7
Step-by-step explanation:
-1.3+4.6x=0.3+4x
4.6x-4x=0.3+1.3
0.6x=1.6
x=1.6/0.6=8/3
x=8/3 OR 2.7
Hope this helps!
Answer:
[tex]\boxed{x = 2\frac{2}{3} }[/tex]
Step-by-step explanation:
[tex]-1.3+4.6x = 0.3 +4x[/tex]
Collecting like terms
[tex]4.6 x -4x = 0.3+1.3[/tex]
[tex]0.6x = 1.6[/tex]
Dividing both sides by 0.6
x = 1.6 / 0.6
x = 2 2/3
Express 0.325 as a percentage
Answers
Answer:
32.5%
Step-by-step explanation:
0.325 x 100%=32.5%
And 0.325 is question
So .0325*100=32.5
Can someone please help!
Answers
Working backwards, on Wednesday morning we have 60 / (1/2) = 120 pounds of ice.
2/3 melts on Tuesday so 120 pounds must be 1/3 of the ice.
120 / (1/3) = 360
Answer: D. 360