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Stats University plans to open a new cafe on campus and would like to solicit students' opinions before launching the project. The administration believes that 70% of the students are in favor of the cafe. They randomly sample 150 students and find that 110 of them support the cafe. Does this sample provide enough evidence to support the administration's belief?

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Final answer:

To determine whether the sample of 150 students provides enough evidence to support the administration's belief that 70% of students are in favor of the cafe, we must conduct a hypothesis test for proportions. The sample proportion of 0.73 must be compared to the null hypothesis of 0.70 using a standard error calculation and a z-test to draw a conclusion.

Step-by-step explanation:

The Stats University administration's belief that 70% of students are in favor of the new cafe can be tested using a hypothesis test for proportions. With a sample of 150 students, we find that 110 support the cafe, which is a sample proportion (π) of 110/150 = 0.73. To determine if this sample provides enough evidence to support the administration's belief, we conduct a hypothesis test.

The null hypothesis (H0) would be that the true proportion of students who support the cafe is 0.70 (π = 0.70). The alternative hypothesis (Ha) could be that the true proportion is different from 0.70. We calculate the standard error of the sample proportion using the formula SE = √[p(1-p)/n], where p is the assumed population proportion (in this case, 0.70), and n is the sample size. The test statistic (z) is calculated as (sample proportion - population proportion) / SE. This z-value is then compared against a critical value from the z-table corresponding to the chosen significance level (commonly α = 0.05 for a two-tailed test).

Without carrying out the complete calculations and assuming the normality conditions are met, if the calculated z-value is less than the critical value, we would not reject the null hypothesis, implying the sample does not provide enough evidence against the administration's belief. Otherwise, if the z-value is higher, the sample would provide sufficient evidence to doubt the belief that 70% of students favor the cafe. However, to make a definitive conclusion, one must conduct the exact calculations and compare against the critical z-value.

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