/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q 59. Oil and residuals The Trans-Alas... [FREE SOLUTION] | 91影视

91影视

Oil and residuals The Trans-Alaska Oil Pipeline is a tube that is formed from 1/2-inch-thick steel and carries oil across 800miles of sensitive arctic and subarctic terrain. The pipe segments and the welds that join them were carefully examined before installation. How accurate are field measurements of the depth of small defects? The figure below compares the results of measurements on 100defects made in the field with measurements of the same defects made in the laboratory. The line y=x is drawn on the scatterplot.

(a) Describe the overall pattern you see in the scatterplot, as well as any deviations from that pattern.

(b) If field and laboratory measurements all agree, then the points should fall on the y=x line drawn on the plot, except for small variations in the measurements. Is this the case? Explain.

(c) The line drawn on the scatterplot (y=x) is not the least-squares regression line. How would the slope and y-intercept of the least-squares line compare? Justify your answer.

Short Answer

Expert verified

Part (a) There is a linear association between the two variables. For small values of laboratory measurement, the line fits very well but for higher values of laboratory, measurement points deviate much from the line.

Part (b) No, the points do not fall on they=x the line drawn on the plot

Part (c) Slope decreases, y-intercept increases.

Step by step solution

01

Part (a) Step 1: Given information

02

Part (a) Step 2: Concept

A regression line is a straight line that depicts the change in a response variable y when an explanatory variable xchanges. By putting this xinto the equation of the line, you may use a regression line to predict the value of yfor any value of x

03

Part (a) Step 3: Explanation

The general pattern moves from bottom left to higher right, as shown in the graph. In other words, higher laboratory measurement usually translates into higher field measurement. Between the two variables, there is a positive linear relationship. The line fits quite well for small values of laboratory measurement, while measurement points depart greatly from the line for larger values of laboratory measurement.

04

Part (b) Step 1: Explanation

Let's start with the scatterplot displayed here: if all field and laboratory measurements agree that each and every data point should sit exactly on this line, the field and laboratory measurements will be perfectly correlated. This is not the case in this illustration. In comparison to tiny measurements, variance is high for bigger values of measurement. As a result, the points do not fall on the plot's y=x line. Because the scatterplot's points to the right all fall below the line y=x (except for one), the points do not roughly fall one y=x line, implying that field and laboratory data may differ.

05

Part (c) Step 1: Explanation

When y = x is compared to the least-square line y=a+bx, the y-intercept is 0and the slope is 1When the explanatory variable x=0, the predicted response of y=0is shown as intercept=0Slope=1 indicates that as the explanatory variable x varies, the expected response ofychanges along the line. When x grows by one unit, y increases by one unit.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Do heavier people burn more energy? Metabolic rate, the rate at which the body consumes energy, is important in studies of weight gain, dieting, and exercise. We have data on the lean body mass and resting metabolic rate for 12women who are subjects in a study of dieting. Lean body mass, given in kilograms, is a person鈥檚 weight leaving out all fat. Metabolic rate is measured in calories burned per 24hours. The researchers believe that lean body mass is an important influence on metabolic rate.

(a) Make a scatterplot on your calculator to examine the researchers鈥 belief.

(b) Describe the direction, form, and strength of the relationship.

Data on dating A student wonders if tall women tend to date taller men than do short women. She measures herself, her dormitory roommate, and the women in the adjoining rooms. Then she measures the next man each woman dates. Here are the data (heights in inches):

(a) Make a scatterplot of these data. Based on the scatterplot, do you expect the correlation to be positive or negative? Near 1or not?

(b) Find the correlation r step-by-step. First, find the mean and standard deviation of each variable. Then find the six standardized values for each variable. Finally, use the formula for r. Do the data show that taller women tend to date taller men?

When it rains, it pours The figure below plots the record-high yearly precipitation in each state against that state鈥檚 record-high 24-hour precipitation. Hawaii is a high outlier, with a record-high yearly record of 704.83 inches of rain recorded at Kukui in 1982

(a) The correlation for all 50 states in the figure is 0.408 If we leave out Hawaii, would the correlation increase, decrease, or stay the same? Explain.

(b) Two least-squares lines are shown on the graph. One was calculated using all 50 states, and the other omits Hawaii. Which line is which? Explain.

(c) Explain how each of the following would affect the correlation, s, and the least-squares line:

  • Measuring record precipitation in feet instead of inches for both variables.
  • Switching the explanatory and response variables.

Born to be old? Is there a relationship between the gestational period (time from conception to birth) of an animal and its average life span? The figure shows a scatterplot of the gestational period and average life span for 43 species of animals.

(a) Describe the direction, form, and strength of the scatterplot.

(b) Three 鈥渦nusual鈥 points are labeled on the graph: Point A is for the hippopotamus, Point B is for the giraffe, and Point C is for the Asian elephant. In what way is each of these animals 鈥渦nusual鈥?

Does social rejection hurt? We often describe our emotional reaction to social rejection as 鈥減ain.鈥 Does social rejection cause activity in areas of the brain that are known to be activated by physical pain? If it does, we really do experience social and physical pain in similar ways. Psychologists first included and then deliberately excluded individuals from a social activity while they measured changes in brain activity. After each activity, the subjects filled out questionnaires that assessed how excluded they felt. The table below shows data for 13subjects.7鈥淪ocial distress鈥 is measured by each subject鈥檚 questionnaire score after exclusion relative to the score after inclusion. (So values greater than 1show the degree of distress caused by exclusion.) 鈥淏rain activity鈥 is the change in activity in a region of the brain that is activated by physical pain. (So positive values show more pain.)

Discuss what the data show. Follow the four-step process.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.