HELP
Posted: Wed May 11, 2022 1:55 pm
HELP
Two random samples of students at a school are taken. Both groups are asked if they wish to continue their education by going to college. A summary of the sample sizes and proportions of each group answering yes" are given below: = UVA (Pop. 1): Ni UNC (Pop. 2): n2 | 81, P1 = 0.767 87, Ô2 - 0.651 = Find a 99% confidence interval for the difference P1 – P2 of the proportions. Express your answer as an interval in the form (a, b). Confidence interval =
(2 points) (a) Find the size of each of two samples (assume that they are of equal size) needed to estimate the difference between the proportions of boys and girls under 10 years old who are afraid of spiders. Assume the "worst case" scenario for the value of both sample proportions. We want a 96% confidence level and for the error to be smaller than 0.09. Answer: (b) Again find the sample size required, as in part (a), but with the knowledge that a similar student last year found that the proportion of boys afraid of spiders is 0.45 and the proportion of girls afraid of spiders was 0.62. Answer:
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(2 points) (a) Find the size of each of two samples (assume that they are of equal size) needed to estimate the difference between the proportions of boys and girls under 10 years old who are afraid of spiders. Assume the "worst case" scenario for the value of both sample proportions. We want a 96% confidence level and for the error to be smaller than 0.09. Answer: (b) Again find the sample size required, as in part (a), but with the knowledge that a similar student last year found that the proportion of boys afraid of spiders is 0.45 and the proportion of girls afraid of spiders was 0.62. Answer: