Concept explainers
Videos
(a)
To explain how does this model compare to the one in previous exercise.
(a)
Answer to Problem 23E
It fits comparably well but slopes are different.
Explanation of Solution
In the previous exercise in the question there was a time plot of the interest rate over the years till 1980 . Now in the question the time plot is showing the trend that changed dramatically after 1980 . The dependent variable is interest rate. Also, it is given that:
R2=74.5%s=1.630Intercept=21.0688Year−1950=−0.356578
Now, from the above information and by looking at the model we can say that this model compare to the previous exercise model fits comparably well but they have very different slopes. As in the previous exercise it is positive and now it is negative.
(b)
To explain what does this model estimate the interest rate to have been in 2000 and how does this compare to the rate you predicted in previous exercise.
(b)
Answer to Problem 23E
It is 3.24% .
Explanation of Solution
In the previous exercise in the question there was a time plot of the interest rate over the years till 1980 . Now in the question the time plot is showing the trend that changed dramatically after 1980 . The dependent variable is interest rate. Also, it is given that:
R2=74.5%s=1.630Intercept=21.0688Year−1950=−0.356578
Now, we predict that the interest rate to have been in 2000 will be as 3.24% that is much lower than the other model predicts.
(c)
To explain do you trust this newer predicted value or not.
(c)
Answer to Problem 23E
Yes, it can be trusted.
Explanation of Solution
In the previous exercise in the question there was a time plot of the interest rate over the years till 1980 . Now in the question the time plot is showing the trend that changed dramatically after 1980 . The dependent variable is interest rate. Also, it is given that:
R2=74.5%s=1.630Intercept=21.0688Year−1950=−0.356578
Now, we can trust the new predicted value because it is in the middle of the data used for the regression. Thus, the new model can be useful. And it will give the accurate results.
(d)
To explain what would you predict the interest rate on three-month treasury bills will be in 2020 .
(d)
Answer to Problem 23E
No, we cannot predict.
Explanation of Solution
In the previous exercise in the question there was a time plot of the interest rate over the years till 1980 . Now in the question the time plot is showing the trend that changed dramatically after 1980 . The dependent variable is interest rate. Also, it is given that:
R2=74.5%s=1.630Intercept=21.0688Year−1950=−0.356578
We cannot predict the interest rate on three-month treasury bills will be in 2020 because it can be different for the different years and by following the previous trend than the future years interest rates are very difficult to predict.
Chapter 9 Solutions
Stats: Modeling the World Nasta Edition Grades 9-12
Additional Math Textbook Solutions
Thinking Mathematically (6th Edition)
College Algebra with Modeling & Visualization (5th Edition)
Elementary Statistics (13th Edition)
Using and Understanding Mathematics: A Quantitative Reasoning Approach (6th Edition)
Elementary Statistics: Picturing the World (7th Edition)
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