Eight students, randomly selected from a large class, were asked to keep a record of the hours they spent studying before the midterm examination. the following table gives the number of hours these eight students studied before the midterm and their scores on the midterm. hours studied 15 7 12 8 18 6 9 11 midterm score 97 78 87 92 89 57 74 69 a) do the midterms scores depend on hours studied or do hours studied depend on the midterm scores? do you expect a positive or a negative relationship between these two variables? b) taking hours studied as an independent variable and midterm scores as a dependent variable compute s xx , s yy and s xy . c) find the least squares regression line. d) interpret the meaning of the values of a and b calculated in part (c). e) plot the scatter diagram and the regression line. f) calculate r . g) calculate also the coefficient of determination.

Ascientist studied a population of workers to determine whether verbal praise and/or tangible rewards affect employee productivity. in the study, some workers were offered verbal praise, some were offered tangible rewards (gift cards, presents, and some were offered neither. the productivity of each participant was measured throughout the study by recording the number of daily tasks completed by each employee. which inference might the scientists make based on the given information? a.) the number of daily tasks completed by each employee may influence the dependent variable, which is whether the employee receives verbal praise, tangible rewards, or neither. b.) verbal praise and/or tangible rewards may influence the independent variable, which is the number of daily tasks completed by each employee. c.) verbal praise and/or tangible rewards may influence the dependent variable, which is the number of daily tasks completed by each employee. d.) the dependent variables, which are verbal praise and tangible rewards, may influence the number of daily tasks completed by each employee.