Question

After the schedule adjustment, the first 36 runs were an average of 8 minutes late. As a result, the Boston public school district claimed that the schedule adjustment was an improvement-students were not as late. Assume a population standard deviation for bus arrival time of 12 minutes. Calculate the value of the test statistic

Answer 1

The value of test statistic is -2.

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,
`\bar{x}` = 8 minutes

Sample size, n = 36

Population standard deviation, σ = 12 minutes

Formula:

`z_(stat) = \displaystyle\frac{\bar{x} - \mu}{(\sigma)/(√(n)) }`

Putting all the values, we have

`z_(stat) = \displaystyle(8 - 12)/((12)/(√(36)) ) = -2`

The value of test statistic is -2.