Question

In a survey of consumers aged 12 and​ older, respondents were asked how many cell phones were in use by the household.​ (no two respondents were from the same​ household.) among the​ respondents, 215215 answered​ "none," 280280 said​ "one," 362362 said​ "two," 149149 said​ "three," and 140140 responded with four or more. a survey respondent is selected at random. find the probability that​ his/her household has four or more cell phones in use. is it unlikely for a household to have four or more cell phones in​ use? consider an event to be unlikely if its probability is less than or equal to 0.05.

Answer 1

A. Let us tabulate the data:

none – 215 respondents

one – 280 respondents

two – 362 respondents

three – 149 respondents

four or more – 140 respondents

So the total number of respondents are:

total = 1146

So the probability that the selected household has four or more cell phones is:

P = 140 / 1146 = 0.122

So there is a 0.122 chance or 12.2% chance that the selected household has four or more cell phones.

B. Since P > 0.05, therefore it is not an unlikely event.