Question

Speed, size, and strength are thought to be important factors in football performance. The article "Physical and Performance Characteristics of NCAA Division I Football Players" (Research Quarterly for Exercise and Sport [1990]: 395–401) reported on physical characteristics of Division I starting football players in the 1988 football season. Information for teams ranked in the top 20 was easily obtained, and it was reported that the mean weight of starters on top-20 teams was 105 kg. A random sample of 33 starting players (various positions were represented) from Division I teams that were not ranked in the top 20 resulted in a sample mean weight of 103.3 kg and a sample standard deviation of 16.3 kg. Is there sufficient evidence to conclude that the mean weight for non-top-20 starters is less than 105, the known value for top-20 teams?

Answer 1

Answer:

no

Explanation:

H0: mean of sample=105

Ha: mean of sampe≠ 105

t-statistic= (population mean-sample mean)/(standard deviation/√sample size)

t-statistic= (105-103.3)/(16.3/√33)

t-statistic= 0.5991

degress of freedom= 32

for alpha 0.05, p-value from t-distributino table is 1.697

since t-statistic is less than the p-value, null hypothesis is accepted.

There is no sufficient evidence to conclude that the mean weight for non-top-20 starters is less than 105 the known value for top-20 teams