A survey published in the American Journal of Sports Medicine2 reported the number of meters (m) per week swum by two groups of swimmers-those who competed exclusively in breaststroke and those who competed in the individual medley (which includes breaststroke). The number of meters per week practicing the breaststroke was recorded for each swimmer, and the summary statistics are given below. Is there sufficient evidence to indicate that the average number of meters per week spent practicing breaststroke is greater for exclusive breaststrokers than it is for those swimming individual medley?
Specially
|
|
Exclusively Breaststroke
|
Individual Medley
|
|
Sample site
|
130
|
80
|
|
Sampk mean (m)
|
9017
|
5853
|
|
Sample standard deviation (m)
|
7162
|
1961
|
|
Population mean
|
μ1
|
μ2
|
a State the null and alternative hypotheses.
b What is the appropriate rejection region for an α = .01 level test?
c Calculate the observed value of the appropriate test statistic.
d What is your conclusion?
e What is a practical reason for the conclusion you reached in part (d)?