
Concept explainers
True or false If false, explain briefly.
- a) We choose the linear model that passes through the most data points on the
scatterplot . - b) The residuals are the observed y-values minus the y-values predicted by the linear model.
- c) Least squares means that the square of the largest residual is as small as it could possibly be.
a.

Find whether the given statement is true or false.
Answer to Problem 1E
The given statement is false.
Explanation of Solution
Given info:
The linear model, which passes through the most data points on the scatterplot, are chosen.
Justification:
If the line passes through the most data points on the then that line won’t be straight line. The line touches some of the points or none of the points, but it minimize the sum of least squares.
Thus, the given statement is false.
The conditions for a scatterplot that is well fitted for the data are,
- Straight Enough Condition: The relationship between y and x straight enough to proceed with a linear regression model.
- Outlier Condition: No outlier must be there which influences the fit of the least square line.
- Thickness Condition: The spread of the data around the generally straight relationship seem to be consistent for all values of predictor variable.
b.

Find whether the given statement is true or false.
Answer to Problem 1E
The given statement is true.
Explanation of Solution
Given info:
The residuals are the observed y-values minus the predicted y-values by the linear model.
Justification:
The residual gives the difference between the observed value of the response variable and that of the predicted value.
Thus, the given statement is true.
Residual:
The residual is defined as
c.

Find whether the given statement is true or false.
Answer to Problem 1E
The given statement is false.
Explanation of Solution
Given info:
Least square defines the square of the largest residual is as small as it could possibly be.
Justification:
A least square criterion defines the unique line that minimize the variance of residuals or sum of squared of the residuals. It does not imply to minimize the largest residual is as small as it could possibly be.
Thus, the given statement is false.
Least-square criterion:
The least-square criterion is of a regression line that the best fits of a set of data points having the smallest possible sum of squares.
Want to see more full solutions like this?
Chapter 7 Solutions
Intro Stats, Books a la Carte Edition (5th Edition)
Additional Math Textbook Solutions
University Calculus
Elementary & Intermediate Algebra
Precalculus: Mathematics for Calculus (Standalone Book)
Elementary Algebra For College Students (10th Edition)
Elementary Statistics: Picturing the World (7th Edition)
A Problem Solving Approach To Mathematics For Elementary School Teachers (13th Edition)
- Suppose that the chance that an elementary student eats hot lunch is 30 percent. What’s the chance that, among 20 randomly selected students, between 6 and 8 students eat hot lunch (inclusive)?arrow_forwardBob’s commuting times to work are varied. He makes it to work on time 80 percent of the time. On 12 randomly selected trips to work, what’s the chance that Bob makes it on time at least 10 times?arrow_forwardYour chance of winning a small prize in a scratch-off ticket is 10 percent. You buy five tickets. What’s the chance you will win at least one prize?arrow_forward
- Suppose that 60 percent of families own a pet. You randomly sample four families. What is the chance that two or three of them own a pet?arrow_forwardIf 40 percent of university students purchase their textbooks online, in a random sample of five students, what’s the chance that exactly one of them purchased their textbooks online?arrow_forwardA stoplight is green 40 percent of the time. If you stop at this light eight random times, what is the chance that it’s green exactly five times?arrow_forward
- If 10 percent of the parts made by a certain company are defective and have to be remade, what is the chance that a random sample of four parts has one that is defective?arrow_forwardQuestion 4 Fourteen individuals were given a complex puzzle to complete. The times in seconds was recorded for their first and second attempts and the results provided below: 1 2 3 first attempt 172 255 second attempt 70 4 5 114 248 218 194 270 267 66 6 7 230 219 341 174 8 10 9 210 261 347 218 200 281 199 308 268 243 236 300 11 12 13 14 140 302 a. Calculate a 95% confidence interval for the mean time taken by each individual to complete the (i) first attempt and (ii) second attempt. [la] b. Test the hypothesis that the difference between the two mean times for both is 100 seconds. Use the 5% level of significance. c. Subsequently, it was learnt that the times for the second attempt were incorrecly recorded and that each of the values is 50 seconds too large. What, if any, difference does this make to the results of the test done in part (b)? Show all steps for the hypothesis testarrow_forwardQuestion 3 3200 students were asked about the importance of study groups in successfully completing their courses. They were asked to provide their current majors as well as their opinion. The results are given below: Major Opinion Psychology Sociology Economics Statistics Accounting Total Agree 144 183 201 271 251 1050 Disagree 230 233 254 227 218 1162 Impartial 201 181 196 234 176 988 Total 575 597 651 732 645 3200 a. State both the null and alternative hypotheses. b. Provide the decision rule for making this decision. Use an alpha level of 5%. c. Show all of the work necessary to calculate the appropriate statistic. | d. What conclusion are you allowed to draw? c. Would your conclusion change at the 10% level of significance? f. Confirm test results in part (c) using JASP. Note: All JASP input files and output tables should be providedarrow_forward
- Question 1 A tech company has acknowledged the importance of having records of all meetings conducted. The meetings are very fast paced and requires equipment that is able to capture the information in the shortest possible time. There are two options, using a typewriter or a word processor. Fifteen administrative assistants are selected and the amount of typing time in hours was recorded. The results are given below: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 typewriter 8.0 6.5 5.0 6.7 7.8 8.5 7.2 5.7 9.2 5.7 6.5 word processor 7.2 5.7 8.3 7.5 9.2 7.2 6.5 7.0 6.9 34 7.0 6.9 8.8 6.7 8.8 9.4 8.6 5.5 7.2 8.4 a. Test the hypothesis that the mean typing time in hours for typewriters is less than 7.0. Use the 1% level of significance. b. Construct a 90% confidence interval for the difference in mean typing time in hours, where a difference is equal to the typing time in hours of word processors minus typing time in hours of typewriter. c. Using the 5% significance level, determine whether there is…arrow_forwardIllustrate 2/7×4/5 using a rectangular region. Explain your work. arrow_forwardWrite three other different proportions equivalent to the following using the same values as in the given proportion 3 foot over 1 yard equals X feet over 5 yardsarrow_forward
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtElementary Linear Algebra (MindTap Course List)AlgebraISBN:9781305658004Author:Ron LarsonPublisher:Cengage Learning
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillAlgebra and Trigonometry (MindTap Course List)AlgebraISBN:9781305071742Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning





