Question

The contingency table below shows the results of a survey of video viewing habits by age. Video Viewing Platform Preferred Viewer Age Mobile/Laptop Device TV Screen Row Total 18–34 34 34 68 35–54 12 12 24 55+ 2 6 8 Column Total 48 52 100 Find the following probabilities or percentages: (a) Probability that a viewer is aged 18–34. (Round your answer to 2 decimal places.) Probability (b) Probability that a viewer prefers watching videos on a TV screen. (Round your answer to 2 decimal places.) Probability (c) Percentage of viewers who are 18–34 and prefer videos on a mobile or laptop device. Percentage of viewers % (d) Percentage of viewers given they are 18–34 who prefer videos on a mobile or laptop device. (Round your answer to 2 decimal places.) Percentage of viewers % (e) Percentage of viewers who are 35–54 or prefer videos on a mobile or laptop device. Percentage of viewers %

Answer 1

	Mobile/Laptop	TV screen	total
18-34	34	34	68
35-54	12	12	24
55+	2	6	8
total	48	52	100 (total people)

a.

P(18-34) = (no. of people aged 18-34) / (total people)

= 68 / 100

= 68%

b.

P(TV screen) = (no. of people that prefer TV screen) / (total people)

= 52 / 100

= 52%

c.

P(18-34 and mobile/laptop) = (no. of people aged 18-34 and prefer mobile/laptop) / (total people)

= 34/100

= 34%

d.

P(mobile/laptop | 18-34) = (no. of people aged 18-34 and prefer mobile/laptop) / (no. of people aged 18-34)

= 34 / 68

= 50%

e.

P( 35–54 or prefer videos on a mobile or laptop device)

= (no. of viewer who are 35–54 or prefer videos on a mobile or laptop device) / (total people)

= (12+12+34+2)/100

= 60%

(please UPVOTE)