Question

Please help I dont know where to start

the standard deviation of a simple random sample of 40 calling times on a payphone is found to be 2.6 minutes. find the test statistic to test a claim that the standard deviation of all phone calls on a payphone is less than 2.9 minutes. use a 0.05 significance level

32.152

31.348

48.519

34.966

Answer 1

Option B) 31.348

Explanation:

We are given the following in the question:

Sample size, n = 49

Sample standard deviation, s = 2.6 minutes

Population standard deviation,
`\sigma` = 2.9 minutes

Significance level,
`\alpha` = 0.05

We have o find the test statistic.

Formula:

`\chi^2 = ((n-1)s^2)/(\sigma^2)\\\\\chi^2 =\displaystyle((40-1)(2.6)^2)/((2.9)^2)\\\\\chi^2=31.348`

Thus, the test statistic is

Option B) 31.348