Answer:
A sample of at least 541 is needed if we wish to be 98% confident that our sample mean will be within 4 hours of the true mean.
Step-by-step explanation:
We are given that an electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours.
We have to find a sample such that we are 98% confident that our sample mean will be within 4 hours of the true mean.
As we know that the Margin of error formula is given by;
The margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
where, [tex]\sigma[/tex] = standard deviation = 40 hours
n = sample size
[tex]\alpha[/tex] = level of significance = 1 - 0.98 = 0.02 or 2%
Now, the critical value of z at ([tex]\frac{0.02}{2}[/tex] = 1%) level of significance n the z table is given as 2.3263.
So, the margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
[tex]4=2.3263 \times \frac{40}{\sqrt{n} }[/tex]
[tex]\sqrt{n}= \frac{40 \times 2.3263}{ 4}[/tex]
[tex]\sqrt{n}=23.26[/tex]
n = [tex]23.26^{2}[/tex] = 541.03 ≈ 541
Hence, a sample of at least 541 is needed if we wish to be 98% confident that our sample mean will be within 4 hours of the true mean.
How many games are played in a 4 team round robin tournament? (Each team
plays every other team only once.)
Answer: 6
Step-by-step explanation:
If we call each team, A, B, C and D, each team has to play each other team once. Let's call each pairing between 2 teams the 2 teams' letters next to each other, e.g. AB is A playing against B. A has to play against B, C and D so we have AB, AC and AD. So we have 3 so far.
We have already counted that B is playing A but we haven't counted B playing C and D yet so we also have BC and BD. So we have 5 in total
Lastly, C needs to play D, we have already counted C playing B and C playing A so we have CD left. In total that gives 6.
Now we have already included D playing every other team so we don't include any other pairings.
In total, now every team has played every other team giving a total of 6.
(another way of solving this is doing "3!2 but if you haven't learnt factorials yet stick to the first method.
Answer:
6 games.
Step-by-step explanation:
The answer is the number of combinations of 2 from 4
= 4*3 / 2*1
= 6.
What linear function defines the following Arithmetic Sequence?
-8, -4, 0, 4, 8, ...
A : an = -8 + 4(n - 1)
B : an= 8 + 4(n - 1)
C : an = -8 - 4(n - 1)
D : an = 8 - 4(n - 1)
The linear equation defines the arithmetic sequence is an = -8 + 4(n - 1). The correct option is A.
What is an arithmetic progression?The sequence in which every next number is the addition of the constant quantity in the series is termed the arithmetic progression
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that, the sequence is -8, -4, 0, 4, 8, ...
a = -8
d = +4
The expression for the nth term will be written as,
an = a + ( n - 1 ) d
= -8 + ( n - 1 ) 4
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Question 16 (5 points)
Given the recursive formula shown, what are the first 4 terms of the sequence?
Answer:
i think its b
???
Step-by-step explanation:
im sorry if im wrong im not very confident on my answer :(
Answer:
D
Step-by-step explanation:
Most logical looking if you look at the formula, the last number has to be smaller than the one before, so.
What is the solution to the quadratic equation x2 + x - 30 = 0?
Answer:
try 3x=30 or 10
Step-by-step explanation:
PLEASE ANSWER QUICK A manufacturing facility pays its employees an average wage of $4.50 an hour with a standard deviation of 50cents. If the wages are normally distributed, what is the percentage of workers getting paid between #3.75 and $5.00 an hour? A. 80.4% B.77.4% C.70.5% D.65.4%
Answer:
B.77.4%
Step-by-step explanation:
Mean wage (μ) = $4.50
Standard deviation (σ) = $0.50
For nay given salary X, the z-score is given by:
[tex]z=\frac{X-\mu}{\sigma}[/tex]
For X = $3.75, the z-score is:
[tex]z=\frac{3.75-4.50}{0.50}\\z=-1.5[/tex]
For X = $5.00, the z-score is:
[tex]z=\frac{5.00-4.50}{0.50}\\z=1[/tex]
A z-score of -1.5 corresponds to the 6.68th percentile, while a score of 1 corresponds to the 84.13th percentile. Therefore, the percentage of workers getting paid between $3.75 and $5.00 an hour is:
[tex]P=84.13-6.68\\P=77.45\%[/tex]
The answer is alternative B.77.4%
hellllllllppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp
Answer:
see below.
Step-by-step explanation:
1st row has four small boxes
2nd row has three big boxes
big box 1 has no items ragged in it.
big box 2 has small box 1 and also small box 1 dragged into it.
big box 3 has small box 3 and small box 4 dragged into it.
A packet of candles and box of matches cost #420. The candles cost 20 times as much as the matches
Answer:
candles = $400
matches = $20
Step-by-step explanation:
Let cost of candles = $c
Let cost of matches = $m
c = 20 m (20 times m)
c + m = 420
20m + m = 420
21 m = 420
m = 20
c = 20 (20) = 400
State sales tax S S is directly proportional to retail price p p . An item that sells for 142 142 dollars has a sales tax of 12.32 12.32 dollars. Find a mathematical model that gives the amount of sales tax S S in terms of the retail price p p .
Answer: [tex]S=0.087p[/tex] .
Step-by-step explanation:
Equation for direct proportion:
y=kx
, where x= independent variable ,
y=dependent variable.
k= proportionality constant
Here, State sales tax S is directly proportional to retail price p.
Also, dependent variable= S, independent variable =p
Required equation: S= kp
Put S= 12.32 and x= 142
[tex]S=12.32=k(142)\\\\\Rightarrow\ k=\dfrac{12.32}{142}\approx0.087[/tex]
Hence, the required equation is [tex]S=0.087p[/tex] .
Consider the following estimated regression equation based on 10 observations y 29.1270 5906x, 4980x2 011
a. Develop a point estimate of the mean value of y when x 1 = 180 and x 2-310 (to 3 decimals).
b. Develop a point estimate for an individual value of y when x 1 180 and x 2-310 (to 3 decimals)
Answer:
no tiene mas informaion?
Step-by-step explanation:
Find the dimensions of a rectangle with area 512 m2 whose perimeter is as small as possible. (If both values are the same number, enter it into both blanks.)
Answer:
√512 by √512Step-by-step explanation:
Length the length and breadth of the rectangle be x and y.
Area of the rectangle A = Length * breadth
Perimeter P = 2(Length + Breadth)
A = xy and P = 2(x+y)
If the area of the rectangle is 512m², then 512 = xy
x = 512/y
Substituting x = 512/y into the formula for calculating the perimeter;
P = 2(512/y + y)
P = 1024/y + 2y
To get the value of y, we will set dP/dy to zero and solve.
dP/dy = -1024y⁻² + 2
-1024y⁻² + 2 = 0
-1024y⁻² = -2
512y⁻² = 1
y⁻² = 1/512
1/y² = 1/512
y² = 512
y = √512 m
On testing for minimum, we must know that the perimeter is at the minimum when y = √512
From xy = 512
x(√512) = 512
x = 512/√512
On rationalizing, x = 512/√512 * √512 /√512
x = 512√512 /512
x = √512 m
Hence, the dimensions of a rectangle is √512 m by √512 m
A data set is summarized in the frequency table below. Using the table, determine the number of values less than or equal to 6.
Answer:
18
Step-by-step explanation:
Given the above table of the data set, the number of values less than or equal to 6 would be the sum of the frequencies of all values that is equal to or less than 6.
From the table above, we would add up the frequencies of the values of 6 and below, which is:
2 + 3 + 6 + 4 + 3 = 18
Answer = 18
The number of values less than or equal to 6 is 18
Calculation of the number of values:Here the number of values should be less than or equivalent to 6 represent the sum of the frequencies i.e. equal or less than 6
So, here the number of values should be
= 2 + 3 + 6 + 4 + 3
= 18
Hence, we can conclude that The number of values less than or equal to 6 is 18
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The triangles are similar. Write a similarity statement for the triangles.
Answer:
Option (2)
Step-by-step explanation:
In the two triangles ΔWVZ and ΔYXZ,
If the sides WV and XY are parallel and the segments WY and VX are the transverse.
∠X ≅ ∠V [Alternate angles]
∠W ≅ ∠Y [Alternate angles]
Therefore, ΔWVZ ~ ΔYXZ [By AA postulate of the similarity]
Option (2) will be the answer.
help!! I have problem to solve this question
Answer:
Step-by-step explanation:
[tex]\frac{x-1}{2} =t\\\frac{y-2}{3} =t\\\frac{z-3}{4} =t\\so~eq.~of~line~L_{1}~is\\\frac{x-1}{2} =\frac{y-2}{3} =\frac{z-3}{4} \\its~d.r's~are~2,3,4\\again~\frac{x-2}{1} =s\\\frac{y-4}{2} =s\\\frac{z+1}{-4} =s\\so~eq. ~of~line~L_{2}~is\\\frac{x-2}{1} =\frac{y-4}{2} =\frac{z+1}{-4} \\its~d.r's ~are~1,2,-4\\let ~the ~d.r's~of~line~perpendicular~to~both~L_{1}~and~L_{2}~be~a,b,c,~then~\\2a+3b+4c=0\\1a+2b-4c=0\\solving\\\frac{a}{3*-4-4*2} =\frac{b}{4*1-2*-4} =\frac{c}{2*2-3*1} \\[/tex]
[tex]\frac{a}{-20} =\frac{b}{-4} =\frac{c}{1} \\d.r's~of ~reqd~line~is~-20,-4,1~or~20,4,-1[/tex]
now you find the point of intersection.
then calculate the angle.
Solve the equation for the indicated variable. C=680x/h^2 for x
Answer:
C h^2 / 680 = x
Step-by-step explanation:
C=680x/h^2
Multiply each side by h^2
C h^2=680x/h^2 * h^2
C h^2=680x
Divide each side by 680
C h^2 / 680=680x/680
C h^2 / 680 = x
Currently Shawn pays $550 per month to rent his apartment. Next year his rent will increase by 13.5% from what he currently pays . a) find the amount that shawn's rent will increase . b) what will be shawn's new monthly rent?. c) If you divide your answer from (b) by shawn's original rent of $550, what is the decimal result? do you see any connection to part (a)?
a) Simply do 0.135(13.5%)*550 to get that his rent increases by $74.25.
b) Simply do 550+74.25 to get that his new rent is $624.25.
c) 624.25/550 = 1.135, or 100%+13.5%, the amount his rent increased.
Hope it helps <3
Answer:
A. $74.25
B. $624.25
C. 1.135, and this is a connection to part a because it's what we multiplied 550 by to get our new rent.
Step-by-step explanation:
If Shawn pays $550 per month for rent, and he has a 13.5% increase, we can multiply 550 by [tex]1+\frac{13.5}{100}[/tex] to get our new number.
[tex]1+0.135=1.135[/tex]
[tex]550\cdot1.135=624.25[/tex]
This is the new monthly rent, part B. To find Part A, let's subtract 550 from thi number.
[tex]624.25-550=74.25[/tex]
Now, for part C, let's divide 624.25 by 550.
[tex]624.25\div550 = 1.135[/tex]
If you notice, 1.135 is the same number we multiplied 550 by to get our new cost, and as a percent, 1.135 is 113.5%.
Hope this helped!
Drag each tile to the correct box. Order the expressions from least value to greatest value . -3 3/10 - ( -7/20 ), 5/-1.6, 5 6/15 + ( -2 4/5 ), -4.5 x -2.3
Answer:
B A C D
Step-by-step explanation:
Your calculator can tell you the values of these expressions. In the order given, they are ...
-3 3/10 -(-7/20) = -2.955/-1.6 = -3.1255 6/15 +(-2 4/5) = 2.6-4.5×-2.3 = 10.35We hope you have no trouble recognizing that swapping the first two expressions will put them all in increasing order.
-3 3/10 -(-7/20) = -2.95
5/-1.6 = -3.125
5 6/15 +(-2 4/5) = 2.6
-4.5×-2.3 = 10.35
The lowest temperature ever
recorded on earth was -89°C
in Antarctica. The average
temperature on Mars is about
-55°C. Which is warmer?
Write an inequality to support
your answer
Answer:
Mars
Step-by-step explanation:
America
1. An architect is designing a house for the Mullet family. In the design he
must consider the desires of the family and the local building codes. The
rectangular lot on which the house will be built has 91 feet of frontage
on a lake and is 158 feet deep.
Answer:
An architect is designing a house for the Frazier family. In the design he must consider the desires of the family and the local building codes. The rectangular lot on which the house will be built has 91 feet of frontage on a lake and is 158 feet deep.
The building codes states that one can build no closer than 10 ft. to the lot line. Write an inequality and solve to see how long the front of the house facing the lake may be.
------
length = 91 - 2*10 = 71 ft.
-------------------------------
The Fraziers requested that the house contain no less 2800 ft square and no more than 3200 ft square of floor sample. Write an inequality to represent the range of permissible widths for the house.
---------
2800 <= area <= 3200
2800 <= (length)(width) <= 3200
2800 <= 71w <= 3200
39.44 <= width <= 45.07
hope it helpsss
Step-by-step explanation:
Answer: An architect is designing a house for the Frazier family. In the design he must consider the desires of the family and the local building codes. The rectangular lot on which the house will be built has 91 feet of frontage on a lake and is 158 feet deep.
The building codes states that one can build no closer than 10 ft. to the lot line. Write an inequality and solve to see how long the front of the house facing the lake may be.
------
length = 91 - 2*10 = 71 ft.
-------------------------------
The Fraziers requested that the house contain no less 2800 ft square and no more than 3200 ft square of floor sample. Write an inequality to represent the range of permissible widths for the house.
---------
2800 <= area <= 3200
2800 <= (length)(width) <= 3200
2800 <= 71w <= 3200
39.44 <= width <= 45.07
In a box-and-whisker plot, the interquartile
range is a measure of the spread of the
middle half of the data. Find the interquartile
range for the data set: 10, 3, 7, 6, 9, 12, 13.
Answer:
I believe the interquarrile range is 5
The rate of earnings is 6% and the cash to be received in four years is $20,000. The present value amount, using the following partial table of present value of $1 at compound interest, is
Answer:
$15,842
Step-by-step explanation:
We use the Present value formula
Present Value = Future value/(1 + r)ⁿ
r = 6% = 0.06
n = 4 years
Future value = $20,000
Present value = 20,000/(1 + 0.06)⁴
= $15841.873265
≈ $15,842
Circle A has center of (4,6) and a radius of 5, and circle B has a center of (1,0) and a radius of 15. What steps will help show that circle A is similar to circle B? Dilate circle Dilate circle A by a scale factor of 3. translate Circle A using the rule (x - 3, y + 6). Rotate circle A 180° about the center. reflect circle A over the y-axis.
The answer is A. Dilate circle A by a scale factor of 3
I took the test :)
Find the next two !!!
It's adding 3 and subtracting 2 every time.
This means the next two terms would be +3 and -2 since the last one was -2.
The next term = 4+3=7
The next next term = 7-2=5
Answer:
Answer : 7 , 5Please see the attached picture.
Hope it helps...
Best regards!!
Jackson's robot moved 5 meters in 2 seconds How far did he move in 30 sec? (please explain and use fractions)
75 meters
Step-by-step explanation:
5 x 30/2
= 5 x 15
= 75 meters
There are 50 mangoes 20 of which are unriped another basket contains 40 mangoes 15 unripe if we take 1 mangoes from each basket Find the probability of getting both are ripe Find the probability of getting both are unripe Find the probability of getting one ripe and one unripe Find the probability of at least one right Find the probability of at least one uripe
Answer:
probability of getting both are unripe
= 0.15
probability of getting both are ripe
= 0.375
Probability of one ripe and one unripe
=0.234375
Probability of at least one unripe
=0.625
Step-by-step explanation:
50 mangoes 20 of which are unriped in the first basket .
Riped = 50-20= 30
Probability of unripe = 20/50
Probability of unripe= 0.4
Probability of ripe = 30/50
Probability of ripe = 0.6
40 mangoes of which 15 are unripe In the second basket
Number of riped= 40-15= 25
Probability of unriped= 15/40
Probability of unriped= 0.375
Probability of riped= 25/40
Probability of riped= 0.625
probability of getting both are unripe
= 0.4*0.375
probability of getting both are unripe
= 0.15
probability of getting both are ripe
= 0.6*0.625
= 0.375
Probability of one ripe and one unripe
= 0.625*0375
= 0.234375
Probability of at least one unripe
= 1- probability of no unripe
= 1 - probability of both ripe
= 1-0.375
= 0.625
Which Graph represents the solution to the compound inequality 4x +8< -16 or 4x + 8 > 4
Answer:
option 3
Step-by-step explanation:
4x+8<-16
x<-6
4x+8_>-16
x_>-1
(it's more and equal .so the circle has to be shaded and move to the right of -1)
Answer:C
Step-by-step explanation:
The function A(b) relates the area of a trapezoid with a given height of 10 and
one base length of 7 with the length of its other base.
It takes as input the other base value, and returns as output the area of the
trapezoid.
A(b) = 10.57?
Which equation below represents the inverse function B(a), which takes the
trapezoid's area as input and returns as output the length of the other base?
O A. B(a) = -7
B. B(a) = 9, -5
Answer:
[tex]B(a)=\frac{a}{5} -7[/tex]
Step-by-step explanation:
The input it taken as the unknown base value, while the output here is the area of the trapezoid. b is therefore the base value, and A( b ) is the area of the trapezoid. Let's formulate the equation for the area of the trapezoid, and isolate the area of the trapezoid. To find the inverse of this function, switch y ( this is A( b ) ) and b, solving for y once more, y ➡ y ⁻ ¹.
y = height [tex]*[/tex] ( ( unknown base value ( b ) + 7 ) / 2 ),
y = 10 [tex]*[/tex] ( ( b + 7 ) / 2 )
Now switch the positions of y and b -
b = 10 [tex]*[/tex] ( ( y + 7 ) / 2 ) or [tex]b=\frac{\left(y+7\right)\cdot \:10}{2}[/tex] - now that we are going to take the inverse ( y ⁻ ¹ ) or B( a ), b will now be changed to a,
[tex]y+7=\frac{a}{5}[/tex],
[tex]y^{-1}=\frac{a}{5}-7 = B(a)[/tex]
Therefore the equation that represents the inverse function will be the following : B(a) = a / 5 - 7
The graph shows how the length of time a boat is rented is related to the
rental cost. What is the rate of change shown in the graph?
Boat Rental
AY
440
400
380
320
Cost (dollars)
240
200
100
120
80
40
0
Time (hours)
A. $40/hour
B. $80/hour
C. 80 hours/dollar
D. 40 hours/dollar
A slope is also known as the gradient of a line is a number. The correct option is B.
What is Slope?A slope is also known as the gradient of a line is a number that helps to know both the direction and the steepness of the line.
slope = (y₂-y₁)/(x₂-x₁)
The rate of change shown in the graph is the slope of the given line.
Now, to know the slope of the line consider any two points on the line, such as (0,0) and (5,400).
Therefore, the slope of the line can be written as,
Slope, m = ($400 - $0)/(5-0) hour
= $400/5 hour
= $80/hour
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The function h(t) = -4.9t² + 19.6t is used to model the height of an object projected in the air where h(t) is the height (in meters) and t is the time (in seconds). What is the domain and range? Domain:
Answer:
Step-by-step explanation:
when h(t)=0
-4.9 t²+19.6t=0
4.9t(-t+4)=0
either t=0 or t=4
so domain is 0≤t≤4
for range
h(t)=-4.9t²+19.6t
=-4.9(t²-4t+4-4)
=-4.9(t-2)²+19.6
so range is 0≤h≤19.6
Domain = 0<t<4, make sure to use less than or equal to signs not just less than signs.
Range = 0<h<19.6, again, use less than or equal to signs.
During a camping trip, a group went one -third of the total distance by boat, 10km by foot and One – sixth of it by riding horses. Find the total distance of the trip.
Find the measure of the indicated angle to the nearest degree.
PLEASE HELP ASAP
Answers
A. 26
B. 42
C. 64
D. 48
Answer:
The answer is option C
Step-by-step explanation:
To find the indicated angle we use sine
sin ∅ = opposite / hypotenuse
From the question
The opposite is 37
The hypotenuse is 41
So we have
sin ? = 37/41
? = sin-¹ 37/41
? = 64.4805
? = 64° to the nearest degreeHope this helps you
Answer:
C.) 64
Step-by-step explanation:
I got it correct on founders edtell