Questions from Business Statistics

Q: Public health officials believe that 98% of children have been vaccinated

Public health officials believe that 98% of children have been vaccinated against measles. A random survey of medical records at many schools across the country found that, among more than 13,000 chil...

Q: Suppose an advocacy organization surveys 960 Canadians and 192 of them reported

Suppose an advocacy organization surveys 960 Canadians and 192 of them reported being born in another country (www.unitednorthamerica.org/simdiff.htm). Similarly, 170 out of 1250 U.S. citizens reporte...

Q: Non-profits test Complete the analysis begun in Exercise 2 .

Non-profits test Complete the analysis begun in Exercise 2 . 1. What is the difference in the proportions of the two types of companies? 2. What is the value of the z-statistic? 3. What do you conclud...

Q: Do consumers spend more on a trip to Walmart or Target?

Do consumers spend more on a trip to Walmart or Target? Suppose researchers interested in this question collected a systematic sample from 85 Walmart customers and 80 Target customers by asking custom...

Q: A sports reporter suggests that professional baseball players must be, on

A sports reporter suggests that professional baseball players must be, on average, older than professional football players, since football is a contact sport and players are more susceptible to concu...

Q: Using the summary statistics provided in Exercise 11 , researchers calculated a

Using the summary statistics provided in Exercise 11 , researchers calculated a 95% confidence interval for the mean difference between Walmart and Target purchase amounts. The interval was ($14.15, $...

Q: The full series of data giving the median age at first marriage

The full series of data giving the median age at first marriage in the United States for men and women shows the following pattern. 1. In what way do these data differ from standard time series? 2. De...

Q: Using the summary statistics provided in Exercise 12 , the sports reporter

Using the summary statistics provided in Exercise 12 , the sports reporter calculated the following 95% confidence interval for the mean difference between major league baseball players and profession...

Q: The researchers in Exercise 11 decide to test the hypothesis that the

The researchers in Exercise 11 decide to test the hypothesis that the means are equal. The degrees of freedom formula gives 162.75 df. Test the null hypothesis at α=0.05.

Q: The researchers in Exercise 12 decide to test the hypothesis. The

The researchers in Exercise 12 decide to test the hypothesis. The degrees of freedom formula gives 51.83 df. Test the null hypothesis at α=0.05. Is the alternative one- or two-sided?