A statistician decides to test the accuracy of this statement, so he conducts a long-range study....

A statistician decides to test the accuracy of this statement, so he conducts a long-range study. He starts with 1,000 high school seniors, and asks them report their age in years and to count how many “friends” they have. Every year for 25 years, he stays in touch with the students via email and asks them to report their current age and inform him how many friends they have. The statistician averages the number of friends per year and 25 years later, plots the points (age, friends).

The least squares regression line is: Friends= 116.14− 2 .94(Age) The coefficient of determination is: R² = 0.58

a)What is the direction of the association between age and number of friends?

b)What is the correlation coefficient for this data? Describe the strength of the association based on the correlation.

c)Identify and interpret the slope.

d)Interpret R2.

e)What is the predicted number of friends for a 22-year-old?

f)A 30-year-old in the study has 25 friends. What is his residual?

g)At what age does the model suggest you will have only 25 friends?

h)What is the predicted number of friends for a 50-year-old?

Expert Solution

orchestra answered 1 year ago

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