Using the z-distribution, it is found that the smallest sample size required is given by:
B) 7 vehicles.
<h3>What is the margin of error for a z-distribution confidence interval?</h3>
It is given by:
In which:
is the population standard deviation.
In this problem, we have a 90% confidence level, hence
, z is the value of Z that has a p-value of 
, so the critical value is z = 1.645.
The margin of error and the population standard deviation are given by, respectively:
.
Then, we solve for n to find the needed sample size.
Rounding up, 7 vehicles have to be sampled, hence option B is correct.
More can be learned about the z-distribution at brainly.com/question/25890103
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Answer:
a(bc) = (ab)c
Step-by-step explanation:
The associative property of multiplication says the product is the same regardless of how the factors are grouped. That is demonstrated by the equality ...
a(bc) = (ab)c
Summer AND her 3 brothers = 4
$20 divided by 4 = $5
First, let's isolate one of the variables (preferably, y)
5y = -9x + 28
y = -1.8x + 5.6
Input this into the second equation:
5x + 9(-1.8x + 5.6) = 56
5x + -16.2x + 50.4 = 56
-11.2x + 50.4 = 56
-11.2x = 5.6
x = -0.5
Knowing this:
-2.5 + 9y = 56
9y = 58.5
y = 6.5
The solution set is (-0.5, 6.5)
