9. Hypothesis tests about a population proportion A firm's corporate strategy is driven largely by its top management team. One method of gauging the influence of marketing on corporate strategy is to measure the proportion of firms with a chief marketing officer on their top management team. Over the 5-year period from 2000 to 2004, 42% of firms had a chief marketing officer on their top management team. [Source: Pravin Nath and Vijay Mahajan, "Chief Marketing Officers: A Study of Their Presence in Firms'Top Management Teams," Journal of Marketing, 70 (2007).] To test the hypothesis that the influence of marketing on corporate strategy today is different from its influence in the 2000-2004 period, a random sample of 97 U.S. firms is selected. Of these, 31 firms have a chief marketing officer on their top management team. The test is conducted at a significance level of 0 = 0.05.Use the Distributions tool to develop the rejection region. According to the rejection region method (with a = 0.05), when do you reject the null hypothesis? O Reject Ho if t S -1.985 or if t 2 1.985 O Reject Ho if z $ -1.960 O Reject Ho if z S -1.645 or if z 2 1.645 O Reject Ho if z $ -1.960 or if z 2 1.960 Use the provided Distributions tool to determine the p-value. The p-value is Using the rejection region method, the null hypothesis is because . Using the p-value approach, the null hypothesis is because . Therefore, you infer that the influence of marketing on corporate strategy today is different from its influence in the 2000-2004 period