In the least-squares regression model, yi = β1xi + β0 + εi, εi is a random error term with mean ______ and standard deviation σεi = ______.

[DATA] Bear Markets (Refer to Problem 34, Section 4.1) A bear market is a market condition in which the price of the security falls. A bear market in the stock market is defined as a condition in which the market declines by 20% or more over the course of at least two months. The following data represent the number of months and percentage change in the S&P500 (a group of 500 stocks).

d. Based on your results to parts (b) and (c), would you recommend using the least-squares regression line to predict the percent change in the S&P500 during a bear market? Why?

"[DATA] Credit Scores [See Problem 12 in Section 12.3] An economist wants to determine the relation between one’s FICO score, x, and the interest rate of a 36-month auto loan, y. The data represent the interest rate (in percent) a bank might offer on a 36-month auto loan for various FICO scores.

b. Determine the slope of the least-squares regression line between credit score and interest rate."

"[DATA] An Unhealthy Commute [See Problem 11 in Section 12.3] The following data represent commute times (in minutes) and a score on a well-being survey.

b. Determine the slope of the least-squares regression line between commute time and well-being score."

What do the y-coordinates on the least-squares regression line represent?

[DATA] Tar and Nicotine Every year the Federal Trade Commission (FTC) must report tar and nicotine levels in cigarettes to Congress. Tar and nicotine levels of over 1200 brands of cigarettes are given to Congress and a random sample of those appear in the following table:

c. Determine sb_1.

In Problems 5–10, use the results of Problems 7–12, respectively, from Section 4.2 to answer the following questions:

a. What are the estimates of β₀ and β₁?

In Problems 5–10, use the results of Problems 7–12, respectively, from Section 4.2 to answer the following questions:

b. Compute the standard error, the point estimate for σ.

Intervals constructed about the predicted value of y, at a given level of x, that are used to measure the accuracy of a single individual’s prediction are called___________intervals for a(n)_________response.