Technology companies compete to put their products in the hands of consumers. A main point of competition is the market for smartphones, phones capable of acting like a small computer complete with spreadsheets, daily planners, address books, and, of course, games. Major competitors include the iPhone, Blackberry, and various phones using Google€™s Android and Microsoft€™s Windows operating systems. To keep up with the market, media watch companies such as Nielsen watch for trends and collect large surveys of consumer preferences. A survey of about 9,000 consumers in late 2010 produced this contingency table.
The table gives a range for the age of the consumer in the survey and shows each consumer€™s next desired smart-phone preference.

Motivation
(a) What would it mean to find dependence between the age and stated preference?
(b) Why would a company such as Apple or RIM (which makes the Blackberry) be interested in knowing whether the preference for their phone depends on the consumer€™s age?
Method
(c) Verify that the data meets the conditions for the chi-squared test of independence.
(d) What problem is likely if the survey had about 500 consumers?
Mechanics
(e) Compute the test statistic and its p-value.
Message
(f) Show a plot of the data that summarizes the results of the test that emphasizes the different brand preferences within age groups.
(g) Summarize the implications of the test and data.

Transcribed Image Text:

Stated Smartphone Preference 18-24 25-34 35-54 55+ AppleAndroid Blackberry Windows Other 304 324 307 200 991 807 593 437 883 754 618 336 102 159 151 146 119 74 50 Unsure 337 367 512 460 Age