Question

A serviceadvertises that it will take them in average 18 min to fix the problem.  Independent contractor was hired to check how long it will really take to fix the common problem.  Test was done nine times. Table below shows collected results (sample data) in min.

17

19

20

30

29

25

21

24

40

Apply Hypothesis Testing at the 5% level to check if average time of problem solving takes 18 min..
Find Test Statistics, t-value, and p-value to make the decision.

Answer 1

Answer---->>

here Critical value calculate from t-distribution table.