Question

The data {10.1,10.5,11.3,9.4,10,10.7,12.4} means times that a runner records in the 40-yard dash on days she drinks Coca-Tea. Historically she averaged 11.1 seconds per race. Is this sufficient evidence to suggest that drinking Coca-Tea improves her race time? Assume 0.05 significance level.

Answer 1

Sample Mean = 10.63

Sample standard deviation (S) = 0.98

Hypothesis:

Ho: = 11.1

Ha: > 11.1 or drinking Coca-Tea improves her race time

Test statistic:

Degree of freedom = n-1 = 7-1 = 6

Critical value:

                 ...................Using t table

Conclusion:

t > t,n-1, that is -1.27 < 2.4469, That is Fail to Reject Ho at 5% level of significance.

There is Not sufficient evidence to suggest that drinking Coca-Tea improves her race time.