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 was31.45and the sample standard deviation was9.049years. 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? Usea=0.05. Assume the ages of mothers of abnormal male children have a normal distribution.