Reference no: EM133399296

Assignment:

In baseball, as in the rest of the business world, it is generally believed that salary reflects ability. We would, therefore, expect baseball teams with a higher payroll to win more games. Refer to the CSV file in the link below which contains data from the 2009 baseball season.

Data (CSV): baseball.csv Download baseball.csv

Using R

Question 1: Indicate the sample mean payroll price in millions. Round your result to the nearest million.

Question 2: Indicate the corresponding standard deviation. Round your result to the nearest million.

Question 3: What is the correlation coefficient for payroll in millions and number of wins? Round your result to two decimal places.

Question 4: Interpret the correlation coefficient reported above.

The owner of a gasoline service station wants to study whether his advertising campaign has increased the amount of gasoline purchased by motorists at his station. Before the campaign the average purchase was 10 gallons. In a random sample of 60 motorists, the mean purchase is 11.3 gallons with a standard deviation of 3.1 gallons. At the 1% level of significance, test whether the average purchase is larger than 10 gallons.

Question 5: Write down the formal version of the null and alternative hypotheses.

Question 6: Explain why the appropriate test statistic is a t statistic rather than a z-score.

Question 7: Compute the test statistic with 3 decimals.

Question 8: What are the degrees of freedom for the test statistics?

Question 9: What is the critical value for rejecting the null hypothesis? You can either round up or down with your degrees of freedom when you look up the number in the t table.

Question 10: Is there sufficient evidence to reject the null hypothesis? What is your interpretation of this result? Explain briefly.