Question

The number of responses to a survey are shown in the Pareto chart. The survey asked 572 adults how much they trust social networking websites with their personal information. Find the probability of randomly selecting a person from the sample that meet each category. Note that the last category is unsure​ (U). ​(a) Trusts social networking websites a moderate​ (M) amount ​(b) Trusts social networking websites completely​ (C) ​(c) Trusts social networking websites a lot​ (A) or completely​ (C) ​(d) Does not trust social networking websites at all​ (N) or only a little​ (L) N L M A C U 0 25 50 75 100 125 150 175 200 Response Number responding 173 153 149 49 36 12

Answer 1

From the Pareto chart, the frequency table is shown below,

	Frequency	Relative frequency
N	173	0.3024
L	153	0.2675
M	149	0.2605
A	49	0.0857
C	36	0.0629
U	12	0.0210
Total	572

(a) Trusts social networking websites a moderate​ (M) amount ​

(b) Trusts social networking websites completely​ (C) ​

(c) Trusts social networking websites a lot​ (A) or completely​ (C) ​

Since both the events are independent of each other, using the sum of the probabilities law (such that P(X or Y) = P(X) + P(Y) - P(X).P(Y))

(d) Does not trust social networking websites at all​ (N) or only a little​(L)