Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby. This method is designed to increase the likelihood that each baby will be agirl, but assume that the method has noeffect, so the probability of a girl is 0.5

0.5. Assume that the groups consist of 23

23 couples. Complete parts(a) through(c) below.

a. Find the mean and the standard deviation for the numbers of girls in groups of 23

births.

The value of the mean is =

The value of the standard deviation is =

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

Values of girls or fewer are significantly low.

Values of girls or greater are significantly high.

c. Is the result of 19 girls a result that is significantlyhigh? What does it suggest about the effectiveness of themethod?

The result

is

is not

significantlyhigh, because 19

girls is

less than

equal to

greater than

girls. A result of 19 girls would suggest that the method is effective/ ineffective