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 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 48 couples. Complete parts (a) through (c) below. a. Find the mean and the standard deviation for the numbers of girls in groups of 48 births. The value of the mean is muequals nothing. (Type an integer or a decimal. Do not round.) The value of the standard deviation is sigmaequals nothing. (Round to one decimal place as needed.) b. Use the range rule of thumb to find the values separating results that are significantly low or significantly high. Values of nothing girls or fewer are significantly low. (Round to one decimal place as needed.) Values of nothing girls or greater are significantly high. (Round to one decimal place as needed.) c. Is the result of 39 girls a result that is significantly high? What does it suggest about the effectiveness of the method? The result ▼ is is not significantly high, because 39 girls is ▼ equal to greater than less than nothing girls. A result of 39 girls would suggest that the method ▼ is effective. is not effective. (Round to one decimal place as needed.)