A study conducted on people\'s main source of news was based on 200 respondents
ID: 3366571 • Letter: A
Question
A study conducted on people's main source of news was based on 200 respondents between the ages of 36 to 50 years and 200 respondents who were over age 50. Of the 200 respondents who were between the ages of 36 and 50, 64 got Age of R their news primarily from newspapers. Of the 200 respondents who were over age 50, 126 got their news primarily from Newspapers 36-50 Over 50 Total 126 190 74 210 200 200 400 newspapers. Complete parts (a) through (d). Yes No 136 a. What is the probability that an individual respondent got news primarily from newspapers? Round to three decimal places as needed.) b. What is the probability that an individual respondent is over 50 years old? (Round to three decimal places as needed.) c. What is the probability that an individual respondent got news primarily from newspapers or is over 50 years old? ? (Round to three decimal places as needed.) d. Explain the difference in the results in (b) and (c). O A. The probability in part (b) is a marginal probability, while the probability in part (c) is a joint probability O B. The two events in part (c) are collectively exhaustive, while the event in part (b) is not O C. The two events in part (c) are mutually exclusive, but part (b) has only one event O D. The Save for Later MacBook ProExplanation / Answer
(a)
P(Newspaper = Yes) = 190/400 = 0.475
(b)
P(Over 50) = 200/400 = 0.5
(c)
By Addition Theorem:
P(Newspaper = Yes OR Over 50) = P(Newspaper = Yes) + P(Over 50) - P(Newspaper=Yes & Over 50) = 0.475 + 0.5 - 126/400
= 0.475 + 0.5 - 0.315 = 0.66
(d)
Correct option:
A. The probability in part (b) is a marginal probability, while the probability in part (c) is a joint probability.
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