9.21 (a)

	Women	Men	Total
Label	63	27	90
Nonlabel	233	224	457
Total	296	251	547

(b) The expected cell counts are given below. For Women Label users, 48.702 = 90*296/547.

	Women	Men	Total
Label	48.702	41.298	90
Nonlabel	247.298	209.702	457
Total	296	251	547

The terms in the c² statistic are given below. They are summed over the rows and columns. The value of the statistic is the total, 10.9493, with df=(2-1)*(2-1) = 1. This is greater than the 0.001 entry in Table F, so this is very strong evidence of a difference in label preference among men and women.

	Women	Men	Total
Label	4.19762	4.95018	9.1478
Nonlabel	0.82666	0.97487	1.80154
Total	5.02428	5.92505	10.9493

(c) The one-tail p-value would be 0.0005 and the two-tail p-value agrees with the c² p-value.

9.22 (a)

	<40	>40
Total #	601	843
Proportion	0.02662	0.0925267
SE	0.00657	0.0099801

(b) Following table gives expected values.

	<40	>40	Total
Term	39.1233	54.8767	94
Not	561.877	788.123	1350
Total	601	843	1444

Following table gives terms in c² statistic. The value of the statistic is 25.0401 and df=(2-1)*(2-1) = 1. The p-value is essentially 0. Terminations were not made at the same rate in the two age groups.

	<40	>40	Total
Term	13.6667	9.74339	23.4101
Not	0.95161	0.67843	1.63004
Total	14.6183	10.4218	25.0401

9.23 Following table gives expected values.

	<40	>40	Total
Fully	126.598	190.402	317
Usually	338.261	508.739	847
Exceeds	37.1408	55.8592	93
Total	502	755	1257

Following table gives terms in c² statistic. Total statistic is 57.86 and df=(3-1)*(2-1) = 2. The p-value is essentially 0. The two age groups differ in their performance. The difference is not so much in the Usually category, but is mostly in the Fully or Exceeds categories.

	<40	>40	Total
Fully	15.7111	10.4464	26.1575
Usually	1.03811	0.69024	1.72835
Exceeds	18.0044	11.9711	29.9755
Total	34.7536	23.1077	57.8614