
Concept explainers
In the following regression, X = total assets ($ billions), Y = total revenue ($ billions), and n = 64 large banks. (a) Write the fitted regression equation. (b) State the degrees of freedom for a two-tailed test for zero slope, and use Appendix D to find the critical value at α = .05. (c) What is your conclusion about the slope? (d) Interpret the 95 percent confidence limits for the slope. (e) Verify that F= t2 for the slope. (f) In your own words, describe the fit of this regression.
a.

Write the fitted regression equation.
Answer to Problem 68CE
The regression equation is,
Explanation of Solution
Calculation:
An output of a regression is given. The X variable is the total assets and Y be the total revenue.
Regression:
Suppose
Where,
The total sum of squares is denoted as,
The regression sum of squares is denoted as,
The error sum of squares is denoted as,
From the regression the fitted line is denoted as,
From the output,
Hence, the regression equation is,
b.

Find the degrees of freedom for the two-tailed test for zero slope.
Find the critical value at 0.05 level of significanceusing Appendix D.
Answer to Problem 68CE
The degrees of freedom for the two-tailed test for zero slop is62.
The critical value at 0.05 level of significanceis 2.000.
Explanation of Solution
Calculation:
Critical value:
Here from the output, the sample size,
The degrees of freedom is,
For two tailed test, the critical value for t-test will be,
From the Appendix D: STUDENT’S t CRITICAL VALUES:
- • Since 62 is not in the table, so locate the value 60in the column of degrees of freedom.
- • Locate the 0.025 in level of significance.
- • The intersecting value that corresponds to the degrees of freedom 60 with level of significance 0.025 is 2.000.
Thus, the critical-valueusing Appendix D is 2.000.
c.

Make a conclusion about the slope.
Explanation of Solution
Let
Hypotheses:
Null hypothesis:
That is, the slope is zero.
Alternative hypothesis:
That is, the slope is not equal to zero.
Decision rule:
If
If
From the output, the t-statistics is 8.183 and from part (b), the critical value at 0.05 level of significanceis 2.000.
Conclusion:
Here the t-statistics is greater than the critical value at 0.05 level of significance.
That is,
Hence, by the decision rule reject the null hypothesis.
That is, the slope is significantly different from zero.
d.

Interpret the 95% confidence interval for the slope.
Explanation of Solution
The 95% confidence interval for the slope,
Where,
From the output, the 95% confidence interval of the slope is (0.0342, 0.0563).
Interpretation:
From the confidence interval it can be concluded that there is 95% confident that the slope will lie between 0.0342 and 0.0563.
e.

Verify
Explanation of Solution
Calculation:
From the output the F statistic is 66.97.
For the slope the t-statistic is 8.183.
Hence, it can be concluded that
f.

Describe the fit of the regression.
Explanation of Solution
Calculation:
From the output, the R-squared value is 0.519.
The coefficient of determination (
The
Want to see more full solutions like this?
Chapter 12 Solutions
Gen Combo Ll Applied Statistics In Business & Economics; Connect Access Card
- Question: A company launches two different marketing campaigns to promote the same product in two different regions. After one month, the company collects the sales data (in units sold) from both regions to compare the effectiveness of the campaigns. The company wants to determine whether there is a significant difference in the mean sales between the two regions. Perform a two sample T-test You can provide your answer by inserting a text box and the answer must include: Null hypothesis, Alternative hypothesis, Show answer (output table/summary table), and Conclusion based on the P value. (2 points = 0.5 x 4 Answers) Each of these is worth 0.5 points. However, showing the calculation is must. If calculation is missing, the whole answer won't get any credit.arrow_forwardBinomial Prob. Question: A new teaching method claims to improve student engagement. A survey reveals that 60% of students find this method engaging. If 15 students are randomly selected, what is the probability that: a) Exactly 9 students find the method engaging?b) At least 7 students find the method engaging? (2 points = 1 x 2 answers) Provide answers in the yellow cellsarrow_forwardIn a survey of 2273 adults, 739 say they believe in UFOS. Construct a 95% confidence interval for the population proportion of adults who believe in UFOs. A 95% confidence interval for the population proportion is ( ☐, ☐ ). (Round to three decimal places as needed.)arrow_forward
- Find the minimum sample size n needed to estimate μ for the given values of c, σ, and E. C=0.98, σ 6.7, and E = 2 Assume that a preliminary sample has at least 30 members. n = (Round up to the nearest whole number.)arrow_forwardIn a survey of 2193 adults in a recent year, 1233 say they have made a New Year's resolution. Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. The 90% confidence interval for the population proportion p is (Round to three decimal places as needed.) J.D) .arrow_forwardLet p be the population proportion for the following condition. Find the point estimates for p and q. In a survey of 1143 adults from country A, 317 said that they were not confident that the food they eat in country A is safe. The point estimate for p, p, is (Round to three decimal places as needed.) ...arrow_forward
- (c) Because logistic regression predicts probabilities of outcomes, observations used to build a logistic regression model need not be independent. A. false: all observations must be independent B. true C. false: only observations with the same outcome need to be independent I ANSWERED: A. false: all observations must be independent. (This was marked wrong but I have no idea why. Isn't this a basic assumption of logistic regression)arrow_forwardBusiness discussarrow_forwardSpam filters are built on principles similar to those used in logistic regression. We fit a probability that each message is spam or not spam. We have several variables for each email. Here are a few: to_multiple=1 if there are multiple recipients, winner=1 if the word 'winner' appears in the subject line, format=1 if the email is poorly formatted, re_subj=1 if "re" appears in the subject line. A logistic model was fit to a dataset with the following output: Estimate SE Z Pr(>|Z|) (Intercept) -0.8161 0.086 -9.4895 0 to_multiple -2.5651 0.3052 -8.4047 0 winner 1.5801 0.3156 5.0067 0 format -0.1528 0.1136 -1.3451 0.1786 re_subj -2.8401 0.363 -7.824 0 (a) Write down the model using the coefficients from the model fit.log_odds(spam) = -0.8161 + -2.5651 + to_multiple + 1.5801 winner + -0.1528 format + -2.8401 re_subj(b) Suppose we have an observation where to_multiple=0, winner=1, format=0, and re_subj=0. What is the predicted probability that this message is spam?…arrow_forward
- Consider an event X comprised of three outcomes whose probabilities are 9/18, 1/18,and 6/18. Compute the probability of the complement of the event. Question content area bottom Part 1 A.1/2 B.2/18 C.16/18 D.16/3arrow_forwardJohn and Mike were offered mints. What is the probability that at least John or Mike would respond favorably? (Hint: Use the classical definition.) Question content area bottom Part 1 A.1/2 B.3/4 C.1/8 D.3/8arrow_forwardThe details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. What is the simple moving average root mean square error? Round to two decimal places. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85 Question content area bottom Part 1 A. 207.13 B. 20.12 C. 14.39 D. 0.21arrow_forward
- Functions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
- Algebra and Trigonometry (MindTap Course List)AlgebraISBN:9781305071742Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageCollege AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning




