Business Statistics Questions
Week 8 Assignment
65- Scholarship Examination Scores. At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical population standard deviation σ=180 is assumed known. Each year, the assistant dean uses a sample of applications to determine whether the mean examination score for the new freshman applications has changed.
a-State the hypotheses.
b-What is the 95% confidence interval estimate of the population mean examination score if a sample of 200 applications provided a sample mean
x¯=935?
c-Use the confidence interval to conduct a hypothesis test. Using α=.05, what is your conclusion?
d-What is the p-value?
67- Starting Salaries for Business Graduates. Michigan State University’s Collegiate Employment Research Institute found that starting salary for recipients of bachelor’s degrees in business was $50,032 in 2017. The results for a sample of 100 business majors receiving a bachelor’s degree in 2018 showed a mean starting salary of $51,276 with a sample standard deviation of $5200. Conduct a hypothesis test to determine whether the mean starting salary for business majors in 2018 is greater than the mean starting salary in 2017. Use α=.01 as the level of significance.
Week 11
23- Daily Hotel Room Occupancy. Because of staffing decisions, managers of the Gibson-Marimont Hotel are interested in the variability in the number of rooms occupied per day during a particular season of the year. A sample of 20 days of operation shows a sample mean of 290 rooms occupied per day and a sample standard deviation of 30 rooms.
a-What is the point estimate of the population variance?
b-Provide a 90% confidence interval estimate of the population variance.
c-Provide a 90% confidence interval estimate of the population standard deviation.
27-Count Chocula Cereal. Filling boxes with consistent amounts of its cereals is critical to General Mills’s success. The filling variance for boxes of Count Chocula cereal is designed to be
.02ounces2 or less. A sample of 41 boxes of Count Chocula shows a sample standard deviation of .16 ounces. Use α=.05 to determine whether the variance in the cereal box fillings is exceeding the design specification.