Question

Question 1 2 pts Keep your numerical answers rounded to 3 decimal places. There is a plan to conduct a survey to estimate the percentage of adults who have had the chickenpox. Find the minimum number of people who must be surveyed to be 95% confident that the sample percentage is within two percentage points of the true percentage for the population of all adults. A First, assume that nothing is known about the prevalence of chickenpox. Minimum sample size needed: B. Next, assume that 95% of adults have had chickenpox. C. Minimum sample size needed: How do the results from parts (A) and (B) effect the sample size? i. It increases the sample size needed from (A) to (B) by over 1,000 people. ii. It decreases the sample size needed from (A) to (B) by over 1,000 people. iii. It keeps the change in sample sizes to within 500. iv. It has no meaningful effect on the sample sizes required. HTML Editor BIVA-A- IE *311x? E - 2 NVR VVDT 112pt Paragraph

Answer 1

be · Let of these Who dample proportion have chickenpox : (allume) Þ Ov5 For 95% confidence internal Zair = 1.960 24 margin of error ALDO margin of -0.0.2 -0 erres - 2x [B CI-B1_CO Zah l-) 0-02 [from 18 (1.960) 0.5 (1205) N = 0.02 (1-960) 10:5) sm -0.62 SD ✓n li (1.960) (0.5) 0.02 49 (49) 2401 2 n. B let be those the sample proportion who Chickenpox 95% have of Eo. 95

0-02 ch erot Margin Thus. 2-syn (1-3) -0-02 40 (1960) (10-15)[/-0.45)=0-02 (1960) 20.0475 = 0.02 To a Dua 104 Toe (1.960) (10.0475) (0:02 = 21.3586048 121:3586048)2 45.6.189 456 sample sve © 97 decreases Lithe needed from to(B over 1000 people Option 1 is corredi by 7