The formula for this type of question is z=x-u/y
z=-2 (z-value)
u = 27 (mean)
y = 4 (standard deviation)
Therefore -2=x-27/4
You now figure this out like a normal equation
4x-2=4 X x-27/4
-8+27= x-27+27
19=x
Therefore the data value of x is 19
Considering the desired result of the hypothesis test, we the closest mean time to 1.5 hours, hence the correct option is:
C. 1.6 hrs
<h3>What should be the mean?</h3>
The closer the mean is to the sample mean, the less likely we are to reject the null hypothesis.
In this problem, the sample mean is of 1.5 hours, hence, the closest value, considering the absolute value of the difference, is of 1.6 hours, hence option C is correct.
More can be learned about the test of an hypothesis at brainly.com/question/16313918
Answer: Pretty sure the answer is 3.
Step-by-step explanation:
5x -2 = 63
<u> +2 = +2 (add 2 to both sides)</u>
<u>5x = 65 (your equation)</u>
5 5 (divide both sides by 5)
x = 13
Billy is 13 years old.
(check: 13 x 5 - 2 = 63
