Question

The cellular phone market is a huge market, but it's a new one. For the time being, there are few established rules for the production and advertisement of cell phones. ClairLinx Wireless, a start-up cell phone company, is trying to decide if it should market specific phone service plans to specific groups of customers. ClairLinx divides its market of potential customers into three major groups: single, working; married, working; and retired.

ClairLinx surveyed 500 potential customers (chosen at random) and asked each, "Of the following, which do you consider to be the most important feature in a cell phone service plan: free nights and weekends, free long distance and roaming, or free calls to customers with the same company?"

Each of the 500 potential customers in the survey was categorized according to the service plan feature she considers most important and the customer group in which she appears. The data are summarized in Table 1 below. In the cells of this contingency table are three numbers: the first number is the observed cell frequency (fO); the second number is the expected cell frequency (fE) under the assumption that the two variables type of potential customer and choice of service plan feature are not related; and the third number is the value

(Observed Cell Frequency-Expected Cell Frequency)^2/Expected Cell Frequency

The numbers labeled "Total" are totals for observed frequency.

Fill in the missing values of Table 1. Round your expected frequencies to at least two decimal places, and round your (Observed Cell Frequency-Expected Cell Frequency)^2/Expected Cell Frequency values to at least three decimal places. Then, using the 0.05 level of significance, perform a test of the hypothesis that the two variables type of potential customer and choice of service plan feature are not related. Complete Table 2 based on your test.

Table 1: Contingency Table
	Choice of service plan feature
Type of potential customer		Free calls to other customers	Free nights and weekends	Free long-distance and roaming	Total
	Single, working	23	46	74	143
			41.76
			0.430
	Married, working	43	63	90	196
			57.23
			0.582
	Retired	32	37	92	161
		31.56	47.01	82.43
		0.006	2.131	1.111
	Total	98	146	256	500

Table 2: Summary of the Hypothesis Test
The type of test statistic:		(Choose one)ZtChi squareF
The value of the test statistic: (Round your answer to at least two decimal places.)
The critical value for a test at the 0.05 level of significance: (Round your answer to at least two decimal places.)
Can we conclude that the variables type of potential customer and choice of service plan feature are related? Use the 0.05 level of significance.				Yes	No

Answer 1