Assume that different groups of couples use the XSORT method of gender selection and each couple gives birth to one baby. The XSORT method is designed to increase the likelihood that a baby will be a girl, but assume that the method has no effect, so the probability of a girl is 0.5.

Assume that the groups consist of 16 couples.

a. Find the mean and standard deviation for the numbers of girls in groups of 16 births.

b. Use the range rule of thumb to find the values separating results that are significantly low or significantly high.

c. Is the result of 11 girls a result that is significantly high? What does it suggest about the effectiveness of the XSORT method?