Answer:
The test statistic for the hypothesis test to check accountant's claim is 2.036.
Step-by-step explanation:
We are given that an accountant claims to be able to complete a standard tax return in under an hour. For a random sample of 24 tax returns, the accountant averaged 63.2 minutes.
Assume that the population standard deviation is equal to 7.7 minutes and the population is normally distributed.
<u><em>Let </em></u><u><em> = average time to complete a standard tax return.</em></u>
So, Null Hypothesis, :
= 60 minutes {means that an accountant can complete a standard tax return in an hour}
Alternate Hypothesis, :
< 60 minutes {means that an accountant can complete a standard tax return in under an hour}
The test statistics that will be used here is <u>One-sample z test statistics</u> as we know about population standard deviation;
T.S. = ~ N(0,1)
where, = sample average time = 63.2 minutes
= population standard deviation = 7.7 minutes
n = sample of tax returns = 24
So, <u><em>test statistics</em></u> =
= 2.036
Hence, The value of test statistics for the hypothesis test to check accountant's claim is 2.036.