Math Problem Solver

1. It has been suggested that abnormal male children tend to occur more often in children born to older

than average mothers. Case histories of 20 abnormal males were obtained. The mean age of the 20

mothers of these children was 31.45 and the sample standard deviation was 9.049 years. It is known

that the mean age at which mothers in the general population give birth is 28 years. Does the sample

give sufficient evidence to support the claim that the mean age of mothers of abnormal male children is

greater than 28 years? Use a=0.05 . Assume the ages of mothers of abnormal male children have a

normal distribution.