Question

Suppose that the batting average for all major league baseball players after each team completes 100 games through the season is 0.251 and the standard deviation is 0.038. The null hypothesis is that American League infielders average the same as all other major league players. A sample of 36 players taken from the American League reveals a mean batting average of 0.244. What is the value of the test statistic, z (rounded to two decimal places)?

Answer 1

Solution:

null hypothesis:

Alternative hypothesis:   

For 0.05 level with two tailed test, critical value of z=1.960

Decision rule : reject if absolute value of test statistic

Population mean

Sample mean

Sample size   

Population std deviation

Standard error of mean =

Test statistic  

From above test statistics z=-1.11