In the past, the average waiting time per customer at a fast food restaurant has been 7.5 minutes. The customer waiting time has a normal distribution. The manager claims that the use of a new cashier system will decrease the average customer waiting time in the store. A random sample of 16 customer transactions produces a mean waiting time of 6.3 minutes and a standard deviation of 2 minutes.

-What is the value of the appropriate test statistic?
A)t = -1.2
B)t = 2.4
C)t = -2.4
D)t = -0.6
E)t = 9.6

Question

In the past, the average waiting time per customer at a fast food restaurant has been 7.5 minutes. The customer waiting time has a normal distribution. The manager claims that the use of a new cashier system will decrease the average customer waiting time in the store. A random sample of 16 customer transactions produces a mean waiting time of 6.3 minutes and a standard deviation of 2 minutes.

-What is the value of the appropriate test statistic?

-What is the value of the appropriate test statistic?
A)t = -1.2
B)t = 2.4
C)t = -2.4
D)t = -0.6
E)t = 9.6

Quizplus · Accepted Answer

The test statistic for a hypothesis test comparing sample means is calculated using the formula $t = \frac{\bar{x} - \mu}{(s/\sqrt{n})}$, where $\bar{x}$ is the sample mean, $\mu$ is the population mean, $s$ is the sample standard deviation, and $n$ is the sample size. Plugging in the given values: $t = \frac{6.3 - 7.5}{(2/\sqrt{16})} = \frac{-1.2}{0.5} = -2.4$.

In the Past, the Average Waiting Time Per Customer at a Fast