Reference no: EM132371764

Statistics Assignment -

Question 1: Given the following numbers. What is the Pearson's Correlation value between the variable X and the variable Y?

Question 2: A researcher examined how the people's weight affect their salaries. She found that the correlation between weights (measured in lbs.) and salary range (measured in dollars) was .10 Had she measured the weight in Kg instead, what would the correlation have been?

Question 3: A research study found that for the new-coming medical students, the correlation between the trail Medical College Admission Test (MCAT) grades and real MCAT grades was 0.60. The variance of pre-exam grades was 81 and the variance of post-exam grades was 100. Thus, the variance of the difference between pre-exam and post-exam grades is.

Question 4: Body mass index (BMI) is a measure of body composition, which can be used to assess if someone is underweight, healthy weight, overweight but not obese, or obese. It is calculated as a person's weight (measured in Kilograms) divided by his/her height (measured in meters) squared. We recorded 5 students' BMI values and the numbers of hours they exercised in the past week, as following:

What is the value of r?

Question 5: A professor wanted to examine the correlation between people's weights and energy expenditure. Imagine that the correlation between people's weights (measured in lbs.) and energy expenditure (measured in kcal) is 0.67. We can also tell the correlation between people's weights (measured in kg.) and energy expenditure (measured in Joules, an unit for energy) is:

Question 6:

Data Source: Smith and Haddad (2000)

In the figure shown above, the correlation between the percentage of children in each country who are underweight and country's gdp is:

A. Mostly positive

B. Zero

C. Appears to be positive when the gdp is between 0 and 3000 and then appears to be negative when the gdp is between gdp of 3000 and 8000

D. Mostly negative but above about gdp of 3000 it appears to be flat.