Part 1: When testing for significance of the slope between xx and yy, if the P-v
ID: 3062703 • Letter: P
Question
Part 1:
When testing for significance of the slope between xx and yy, if the P-value is found to be 0.000015, then:
A. There must be a linear relationship between xx and yy
B. xx and yy are significantly linearly related
C. xx and yy are not significantly linearly related
D. There must be a cause-effect relationship between xx and yy
Part 2:
Eight pairs of data yield the regression equation y=196.32+2.42xy=196.32+2.42x, with a P-value of 0.293 for the slope. Also, the mean of yy is 73.6.
What is the best predicted value of yy for x=102x=102; (assuming 102 is within the scope of the model)?
A. -443.16
B. 102
C. 73.6
D. 50.52
Part 3:
From a random sample of 9 D colour, VS1 clarity, round-cut diamonds, a gemolist determined a linear regression equation relating the price of the diamond to its size (in carats). The smallest diamond in the set weighed 0.66 carats, and the largest one 1.18 carats. Since the slope of the regression was significant, the gemologist concludes that it is reasonable to use his regression line to predict the price of a colour D, VS1 clarity, round-cut diamond that weights 0.25 carats.
Explanation / Answer
Part 1:
When testing for significance of the slope between xx and yy, if the P-value is found to be 0.000015, then:
Answer. xx and yy are significantly linearly related (Since p-value is low, we reject the null hypothesis)
Part 2:
Eight pairs of data yield the regression equation y=196.32+2.42xy=196.32+2.42x, with a P-value of 0.293 for the slope. Also, the mean of yy is 73.6.
What is the best predicted value of yy for x=102x=102; (assuming 102 is within the scope of the model)?
Answer : 50.52 ( Substituting x=102 in above y equation)