Bob White is performing research on monthly expenses for medical care, comprising over-the-counter medicine. His dependent variable is monthly expenses for medical care where as his independent variable is number of family members. Excel output is given below.
SUMMARY OUTPUT
Regression Satistics
Multiple R 0.695
R Square 0.483
Adjusted R Sq 0.474
Standard Error 55.278
Observation 21
ANOVA
df SS MS F Significance F
Regression 1 99929.47 99929.47 32.70311 0.00016
Residual 19 58057.48 3055.657
Total 20 157987
Coefficients Standard Error t Stat P-value
Intercept 110.47 35.53407 3.109087 0.0057
X 16.83 0.819024 5.718663 0.00016
i) Determine prediction equation?
ii) Based on the model, every additional family member increases predicted costs by how much?
iii) Based on significance F-test, is the model good prediction equation?
iv) What percent of variation in medical expenses is explained by size of family?
v) Can null hypothesis that slope is zero be rejected? Explain why or why not?
vi) Determine value of correlation coefficient?