Using the z-distribution, a sample size of 180 is needed for the estimate.
<h3>What is a z-distribution confidence interval?</h3>
The confidence interval is:
The margin of error is given by:
In which:
is the sample mean.
is the standard deviation for the population.
In this problem, we have a 98% confidence level, hence
, z is the value of Z that has a p-value of 
, so the critical value is z = 2.327.
The population standard deviation is of 
, and to find the sample size, we have to solve for n when M = 4.
Hence:
n = 179.03.
Rounding up, as a sample size of 179 would result in an error slightly above 4, a sample of 180 is needed.
More can be learned about the z-distribution at brainly.com/question/25890103
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Answer:
The length of the pencils is 4.1 inches and for the crayons 1.5 inches
Step-by-step explanation:
We can solve by means of a 2x2 system of equations, we have to:
let "x" be the length of the pencils
let "y" be the length of the crayons
4 * x + 3 * y = 20.9
5 * x + 4 * y = 26.5 => x = (26.5 - 4 * y) / 5
Replacing:
4 * (26.5 - 4 * y) / 5 + 3 * y = 20.9
21.2 - 3.2 * y + 3 * y = 20.9
-0.2 * y = 20.9 - 21.2
y = -0.3 / -0.2
y = 1.5
now for x:
x = (26.5 - 4 * 1.5) / 5
x = 4.1
This means that the length of the pencils is 4.1 inches and for the crayons 1.5 inches
Answer:
d. 42
Step-by-step explanation:
PEDMAS
We do brackets first, so:
4 + 4 = 8
Then multiplication,
5 x 8 = 40
Then addition
40 + 2 = 42
Answer:
Step-by-step explanation:
video store A : 15 + 1.75m
video store B : 7.5 + 2.25m
15 + 1.75m = 7.5 + 2.25m
15 - 7.5 = 2.25m - 1.75m
7.5 = 0.50m
7.5 / 0.50 = m
15 = m <=== there would have to be 15 movie rentals to make them equal
check...
15 + 1.75m 7.50 + 2.25m
15 + 1.75(15) = 7.50 + 2.25(15) =
41.25 41.25
yep...it checks out
