Question

a pizza delivery chain advertises that it will deliver your pizza in 25 minutes from when the order is placed. being a skeptic, you decide to test and see if the mean delivery time is actually more than 25 minutes. for the simple random sample of 10 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 28.8 minutes with a standard deviation of 6.4 minutes. assume that the population distribution is approximately normal. perform a hypothesis test using a 0.01 level of significance. step 2 of 3 : compute the value of the test statistic. round your answer to three decimal places.

Answer 1

Rounded to three decimal places, the test statistic is approximately 1.881.

To perform a hypothesis test, you can use the t-test for the mean. The test statistic can be calculated using the formula:

t= x −μ/s/√n

​where:

x is the sample mean,

μ is the population mean (claimed delivery time),

s is the sample standard deviation,

n is the sample size.

Given the information:

Sample mean (x ) = 28.8 minutes

Population mean (μ) = 25 minutes (claimed delivery time)

Sample standard deviation (s) = 6.4 minutes

Sample size (n) = 10

Let's calculate the test statistic:

t= 28.8/6.4 - 25/ √10

t≈ 3.8/2.02

t≈1.881

Rounded to three decimal places, the test statistic is approximately 1.881.