(Use Excel) An engineer wants to determine the effectiveness of a safety program. He collects annual loss of hours due to accidents in 12 plants...

(Use Excel) An engineer wants to determine the effectiveness of a safety program. He collects annual loss of hours due to accidents in 12 plants "Before and After" the program was put into operation.

PlantBeforeAfterPlantBeforeAfter1125    108    7    96    109    2118    83    8    91    87    3123    100    9    77    64    498    83    10    62    68    574    61    11    87    53    6110    81    12    109    107    

Click here for the Excel Data File

Let the difference be defined as Before - After.

a.Specify the competing hypotheses that determine whether the safety program was effective.

   H0: μD = 0; HA: μD ≠ 0H0: μD ≤ 0; HA: μD > 0H0: μD ≥ 0; HA: μD < 0

b.Using the appropriate commands in Excel, calculate the value of the test statistic. Assume that the hours difference is normally distributed. (Round intermediate calculations to at least 4 decimal places and final to 2 decimal places.)

  Test statistic  

c.At the 5% significance level, specify the critical value(s). (Round your answer to 3 decimal places.)

  Critical value  

d.Is there sufficient evidence to conclude that the safety program was effective?   Yes, since we reject H0No, since we do not reject H0Yes, since we do not reject H0No, since we reject H0