An engineer wants to determine the effectiveness of a safety program. He collect

Question

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.

Let the difference be defined as Before – After.

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

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.)

Plant Before After Plant Before After 1 100      98      7      88      90      2 90      88      8      75      70      3 94      90      9      65      62      4 85      86      10      58      60      5 70      67      11      67      60      6 83      80      12      104      98     

Explanation / Answer

Solutioina:

H0: D = 0;

HA: D 0

program is effective

Output form excel

test statistic t=2.95

Solutionc:

Critical value=2.20

Solutiond:

t stst>t crit

2.95>2.2

t-Test: Paired Two Sample for Means Before after Mean 81.58333 79.08333 Variance 212.9924 211.9015 Observations 12 12 Pearson Correlation 0.979677 Hypothesized Mean Difference 0 df 11 t Stat 2.946898 P(T<=t) one-tail 0.006641 t Critical one-tail 1.795885 P(T<=t) two-tail 0.013283 t Critical two-tail 2.200985

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---