In any research, why is descrbing the variability important?

A researchers says that 50% of the variance in blood pressure can be predicted from HR and that blood pressure is postively associated with HR. What is the correlation between blood pressure and HR?

A statistical program is recommended. A company provides maintenance service for water-filtration systems throughout southern Florida. Customers contact the company with requests for maintenance service on their water-filtration systems. To estimate the service time and the service cost, the company's managers want to predict the repair time necessary for each maintenance request. Hence, repair time in hours is the dependent variable. Repair time is believed to be related to three factors, the number of months since the last maintenance service, the type of repair problem (mechanical or electrical), and the repairperson who performed the service. Data for a sample of 10 service calls are reported in the table below. ŷ = Repair Time in Hours 2.9 3.0 ŷ = 4.8 1.8 2.4 4.9 4.7 4.8 4.4 4.5 Months Since Last Service 2 6 8 3 2 7 9 8 4 6 Type of Repair Electrical Mechanical Electrical Mechanical Electrical Electrical Mechanical Mechanical Electrical Electrical Repairperson Dave Newton Dave…

A researcher is studying the intensity of hurricanes that entered the Gulf of Mexico between 1975-2015 and the average water temperature of the Gulf of Mexico at the hurricane's peak strength. What is the independent and dependent variable in this study?

Once the correlation coefficient is known, how can we find the amount of the shared variance?

What percentage of Contra Costa County adults supports a ban on assault-style weapons? Suppose that we survey a random sample of 100 adults living in Contra Costa County and find that 62% support a ban on assault-style weapons. According to  a  2015 study by  the Pew  Research Center, 57% of U.S.  adults  favor a ban on assault-style weapons. Assuming that the variability in random samples will be the same in Contra Costa County as in the U.S., find the 95% confidence interval to estimate the proportion of CCC adults that favor a ban on assault-style weapons.   g. Are we confident that the percentage of Contra Costa County residents that supports a ban is greater than the percentage nationwide as reported by the Pew Research Center? Why or why not?

When can correlation evidence help answer a casual question?

Explain the concept of Range Restriction, and the issue it may pose to correlation statistics