Exam 4: Regression Analysis: Exploring Associations Between Variables

The following model was created to show the association between the number of massages received per month and self- predicted stress level: Stress level = 10 - 0.02(number of massages per month). The coefficient of determination for the model is 0.066 or 6.6%. Choose the true statement regarding this model.

The table shows the number of minutes ridden on a stationary bike and the approximate number of calories burned. Plot the points on the grid provided then choose the most likely correlation coefficient from the answer choices below.

State the explanatory variable and the response variable.

A horticulturist conducted an experiment on 120 thirty- six inch flower boxes to see if the amount of plant food given to the flower boxes was associated with the number of blooms on the plants. The average amount of plant food given was 31.6 milliliters with a standard deviation of 2.2 milliliters. The average number of blooms was 10.5 with a standard deviation of 1.5. The correlation coefficient was 0.8891. Use the information to calculate the slope of the linear model that predicts the number of blooms from the amount of plant food given. Show your work and round to the nearest hundredth. Write a sentence explaining the meaning of the slope in this context.

The data in the table represent the amount of raw material (in tons)put into an injection molding machine each day (x), and the amount of scrap plastic (in tons)that is collected from the machine every four weeks (y). Also shown below are the outputs from two different statistical technologies (TI- 83/84 Calculator and Excel). A scatterplot of the data confirms that there is a linear association. Report the equation for predicting scrap from raw material using words such as scrap, not x and y. State the slope and intercept of the prediction equation. Round all calculations to the nearest hundredth.

The scatterplot below shows the hat size and IQ of some adults. Is the trend positive, negative, or near zero?

The scatterplot below shows the number of tackles received and the number of concussions received for a team of football players for the most recent season. Choose the statement that best describes the trend.

Suppose that runner height (in inches)and finish time in a 5k (in seconds)have a linear association as evidenced by a scatterplot showing a roughly linear pattern, explain the purpose of finding the equation for the regression line that will relate runner height and finish time. What are the limitations of the regression line? Explain the meaning of the slope and intercept of such a model?

If the correlation between whole milk content per serving and calories per serving for several brands of ice cream is 0.71, report the coefficient of determination (rounded to the nearest tenth of a percent)and explain what it means using a complete sentence. Assume that whole milk content is the predictor and calories per serving is the response, and assume that the association between whole milk content and calories is linear.

Use the data provided in the table below to answer the question. The table shows city size and annual grocery expenditures for eight families. City size is in thousands and expenditures is in hundreds of dollars. -Based on the scatterplot, estimate the correlation coefficient between city size and expenditures for these eight families. Explain your reasons for choosing your estimate.

r = - 0.3120

State the slope and intercept of the regression line and explain each in context. Be sure to explain whether the intercept has a practical meaning in this context.

Which of the following statements regarding the correlation coefficient is not true?

Which of the following statements regarding the correlation coefficient is not true?

Use the regression equation to predict how many children a married couple will have if they live in city with a population of 40,000 people.

Use the following information to answer the question. The following linear regression model can be used to predict ticket sales at a popular water park. Ticket sales per hour = - 631.25 + 11.25(current temperature in °F) -In the NBA, the correlation between "steals per game" and "blocked shots per game" is found to be 0.8045. Choose the statement that is true about the coefficient of determination.

The data in the table represent the amount of pressure (psi)exerted by a stamping machine (x), and the amount of scrap brass shavings (in pounds)that are collected from the machine each hour (y). Also shown below are the outputs from two different statistical technologies (TI- 83/84 Calculator and Excel). A scatterplot of the data confirms that there is a linear association. Report the equation for predicting scrap brass shavings using words such as scrap, not x and y. State the slope and intercept of the prediction equation. Round all calculations to the nearest thousandth.

The following model was created to show the association between the number of massages received per month and self- predicted stress level: Stress level = 10 - 0.02(number of massages per month). The coefficient of determination for the model is 0.066 or 6.6%. Choose the true statement regarding this model.

Use the following information to answer the question. A scatterplot of data from a large sample of adult women shows that height in inches and weight in pounds have a linear association. Shown below are the outputs from two different statistical technologies (TI- 83/84 Calculator and Excel). -Report the equation for predicting weight in pounds from height in inches using words such as weight, not x and y.

The scatterplot below shows the hat size and IQ of some adults. Is the trend positive, negative, or near zero?