Question 3 3 pts A university collected a random sample of 192 rst-year students. The number of weekly study hours was used to predict the student's GPA. The following computer output gives the results from predicting GPA based on weekly study hours. Coefcients Which of the following statements is the best interpretation of the value 0.00333 shown in the output? 0 GPA is predicted to increase by 0.00333 for every one weekly hour increase in study time. O For a student with 0 hours of study time, the GPA is predicted as 0.00333. 0 For a student with a 0 GPA, the predicted study time is 0.00333 weekly hours. 0 Study time is predicted to increase by 0.00333 hours per week for every one additional point in GPA. Question 4 3 pts The following scatterplot shows the score of a student on a gifted screening test and the IQ of the student's mother. Scatterplot of score vs motheriq 170 165 OC 160 score OB 155 O 150 100 105 110 115 120 125 130 135 motheriq Which of the following points is most likely an outlier with respect to the regression of gifted score versus mother's IQ? OC O A O B ODQuestion 5 3 pts A researcher is investigating the length (in cm) and weight (in 02) of avocados. The researcher plans to randomly select 25 avocados from a supermarket in a region and construct a 95 percent condence interval for the slope of the population regression line, where length is the explanatory variable and weight is the response variable. When computing a condence interval for the slope of the population regression line, which of the following is a condition that must be checked? 0 The observations are independent. 0 The values of weight are approximately normally distributed at each value of length. 0 The sum of the residuals is zero. 0 The true relationship between length and weight is linear. O The standard deviation for weight does not vary with length. Question 6 3 pts Protein shakes can contain a lot of sugar. A researcher randomly selected 11 best-selling protein powders and recorded the amount of sugar and the number of calories. The researcher created a least-squares regression model to predict the number of calories given the amount of sugar (grams) and plans to calculate a 95% condence interval for the slope. The graphs below show the scatterplot of the data with the regression model, the residual plot and a histogram of the residuals. Fitted Line Plot Versus Fits calories =136.3 + 3473 Sugar [response is calories) 5 12.01" Mq 65.995 ' R-Sqtouj} 52.1 20' 210 0 2M 1!" 18\" calories Residual O I 170 160 .'us 150 ' 140 0 4 _ 5.0 7.5 10.0 12.5 15.0 175 mu '50 '70 "0 '90 200 Sugar tted Value Histogram (lesponse Is Calnrles) an. Frequency _ _ N . \" . :- p. a 0 Residual Which of the following graphs would the researcher use to verify the condition "the standard deviation of y, 0y , does not vary with x"? O The researcher should check the histogram of the residuals to make sure it appears approximately normal and does not have outliers. O The researcher should check the residual plot to make sure the variability of points from the "0" line does not increase or decrease as x increases. 0 The researcher should check the scatterplot to make sure the points show a linear pattern. O The researcher should check the histogram of the residuals to make sure it is skewed to the right. Question 7 3 pts A regression analysis was conducted to investigate the relationship between the number of calories and the amount of sugar (grams) in protein powder. The analysis was performed on a random sample of 11 observations. Coefcients Constant 136.3 10.3 13.26 0.000 - \" 3.473 0.832 4.17 0.002 1.00 Assume that the conditions for inference for the slope of the regression equation have been met. Which of the following denes the margin of error of a 90 percent condence interval for the slope of the least-squares regression line? 0 1.83(0.832) O 1.80(3.473) O 1.83(3.473) O 1.80(0.832)