Assume that different groups of couples use a particular method of gender select
ID: 3365485 • Letter: A
Question
Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby this mention 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 group consists of 45 couples. A) Find the mean and standard deviation for the number of girls in groups of 45 births. Type the value of the mean as an integer or decimal, do not round. The standard deviation should be rounded to one decimal place as needed. B) Use the range rule of thumb to find the values separating results that are significantly low and significantly high. C) Is the result of 37 girls significantly high? A result of 37 girls would suggest the method is effective or is not effective? Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby this mention 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 group consists of 45 couples. A) Find the mean and standard deviation for the number of girls in groups of 45 births. Type the value of the mean as an integer or decimal, do not round. The standard deviation should be rounded to one decimal place as needed. B) Use the range rule of thumb to find the values separating results that are significantly low and significantly high. C) Is the result of 37 girls significantly high? A result of 37 girls would suggest the method is effective or is not effective? A) Find the mean and standard deviation for the number of girls in groups of 45 births. Type the value of the mean as an integer or decimal, do not round. The standard deviation should be rounded to one decimal place as needed. B) Use the range rule of thumb to find the values separating results that are significantly low and significantly high. C) Is the result of 37 girls significantly high? A result of 37 girls would suggest the method is effective or is not effective?Explanation / Answer
a) Mean = n * p = 45 * 0.5 = 22.5 or 23
SD = sqrt (22.5 * 0.5) = 3.4
b) Here, np > 5 and n(1 - p) > 5
So, we can use normal approximation to binomial:
Low range = Mean - 3 * SD
LR = 22.5 - 3 * 3.4 = 12.3
HR = 22.5 + 3 * 3.4 = 32.7
c) Yes, 37 is significantly high as it is higher than 32.7
It would suggest method is not effective