s154l4.doc - Elementary Statistics: STAT154 – Fall 2018–...

Elementary Statistics: STAT154 – Fall 2018– Lab4
I. A doctor wanted to determine whether there was a relation between a male’s age and
his HDL (so-called “good”) cholesterol. He randomly selected 11 of his patients and
determined their HDL cholesterol. He obtained the following data:
Age: 38 42 46 32 55 52 61 61 26 38 66
HDL: 47 54 64 46 45 50 62 58 37 44 62
Use SPSS or any other software to answer the following questions.
a. Draw a scatter diagram of the data treating age as the predictor variable and HDL as
the response variable. What type of relation, if any, appears to exist between age and
HDL cholesterol?
b. Compute the linear correlation coefficient between age and HDL cholesterol.
Comment on the strength of the linear relationship using the correlation coefficient.
c. Find the least-squares regression line treating age as the predictor variable and HDL as
the response variable.
d. Interpret the intercept and the slope coefficient in the regression line in the context of
the problem.