Just need an answer please.

Question

1. Stephen was reading an article about sleep and brain activity and wondered if there was an association between the average number of hours of sleep a student gets and their score on a test the following day. Stephen gathered data from 20 students in his class and made the following scatterplot.

1. Describe the relationship between hours of sleep and test scores.

Stephen found the line of best fit to be y=3.2003x+64.779.

1. Using the line of best fit, predict the test score, to the nearest tenth, for sleep times of: 3½ hours, 5½ hours, and 8 hours. Plot these points on the graph. Please make them a different color so they are easy to see.

1. Interpret the slope of the line of best fit in context.

1. Of the values –0.8, –0.4, 0, 0.4, and 0.8, which is the best approximation of the correlation coefficient for the linear model? Explain.

Answer 1

1) Test scores show a positive linear correlation with increasing sleep hours.

2) 76.0 82.4 90.4

3) There is an increase of about 3.2 in test score for every additional hour of sleep.

4) Negative correlation coefficients indicate a negative slope, so they are out. Zero would imply no correlation, so zero is out. Both 0.4 and 0.8 indicate a positive correlation. As the data appears to be a relatively tight fit to a straight line, 0.8 seems to be the best approximation.