Blog

EU (European Union) countries report that 46% of their labor force is female. The United Nations wants to determine if the percentage of females in the U.S. labor force is the same.  Based on a sample of 500 employment records, representatives from the United States Department of Labor find that the 95% confidence interval for the proportion of females in the U.S. labor force is .357 to .443.  If the Department of Labor wishes to tighten its interval, they should ________________________ .

A recent poll of 120 adults who frequent the local farmer’s market found that 54 have purchased reusable cloth bags for their groceries.  The 95% confidence interval for the proportion of adults who have purchased reusable cloth bags is ________________________ .

Based on data collected from its production processes, Crosstiles Inc. determines that the breaking strength of its most popular porcelain tile is normally distributed with a mean of 400 pounds per square inch and a standard deviation of 12.5 pounds per square inch.  Based on the 68-95-99.7 Rule, about what percent of its popular porcelain tile will have breaking strengths greater than 412.5 pounds per square inch?

Data were collected on annual personal time (in hours) taken by a random sample of 16 women and 7 men employed by a medium sized company.  The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours.  The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours.  The standard error of the sampling distribution for the difference between the two means is ________________________ .

Data were collected on annual personal time (in hours) taken by a random sample of 16 women (group1) and 7 men (group 2) employed by a medium sized company.  The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours.  The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours.  The Human Resources Department believes that women tend to take more personal time than men because they tend to be the primary child care givers in the family. The correct null and alternative hypotheses to test this belief are ________________________ .

A study examined consumption levels of oil and carbon dioxide emissions for sample of counties. The response variable in this study is ________________________ .

The administration of a large university is interested in learning about the types of wellness programs that would interest its employees.  Suppose that there are five categories of employees (administration, faculty, professional staff, clerical, and maintenance) and the university decides to randomly select ten individuals from each category.  This sampling plan is called ________________________ .

A small independent organic food store offers a variety of specialty coffees.  To determine whether price has an impact on sales, the managers kept track of how many pounds of each variety of coffee were sold last month.     Based on the scatterplot, the linear relationship between number of pounds of coffee sold per week and price is ________________________ .

When is the most effective time to introduce grief counseling?

Data were collected on annual personal time (in hours) taken by a random sample of 16 women (group1) and 7 men (group 2) employed by a medium sized company.  The women took an average of 24.75 hours of personal time per year with a standard deviation of 2.84 hours.  The men took an average of 21.89 hours of personal time per year with a standard deviation of 3.29 hours.  The Human Resources Department believes that women tend to take more personal time than men because they tend to be the primary childcare givers in the family.  The results of the test are t = 2.02 with an associated P-value of 0.0352.  The correct conclusion at α = 0.05 is to ________________________ .