In the Women's Health Initiative Dietary Modification Trial women were randomly assigned to an intervention or a control group. The intervention included counseling sessions designed to reduce fat intake and to increase consumption of fruits and vegetables. Over 6 years data were collected on coronary heart disease (CHD): results are shown in the table. Do the data provide evidence that the intervention makes a difference? The value of the chi-square statistic for this contingency table is χ2s = 0.69.

(a) State the null and alternative hypotheses in symbols.
(b) The (non directional) p-value for the test is 0.407. If α = 0.10, what is your conclusion regarding the hypotheses in (a)?

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Group Intervention Control CHD? Yes No 1,549 2.549 27745 46.286 Total19,54129.294 48,835 1,000 18,541