The circumference is the correct.
It can be found using the formula,
Given

We have to set the restraint

because a square root is non-negative, and thus it can't equal a negative number. With this in mind, we can square both sides:

The solutions to this equation are 7 and -2. Recalling that we can only accept solutions greater than or equal to -1, 7 is a feasible solution, while -2 is extraneous.
Similarly, we have

So, we have to impose

Squaring both sides, we have

The solutions to this equation are 5 and 10. Since we only accept solutions greater than or equal to 7, 10 is a feasible solution, while 5 is extraneous.
Answer:
The value of test statistic is -2.
Step-by-step explanation:
The following information is missing in the question.
The population mean is 12 minutes.
We are given the following in the question:
Population mean, μ = 12 minutes
Sample mean,
= 8 minutes
Sample size, n = 36
Population standard deviation, σ = 12 minutes
Formula:
Putting all the values, we have
The value of test statistic is -2.