- 6 1 (46.5 KiB) Viewed 77 times
6.
-
answerhappygod
- Site Admin
- Posts: 899603
- Joined: Mon Aug 02, 2021 8:13 am
6.
6.
An instructor asked a random sample of eight students to record their study times at the beginning of a course. She then made a table for total hours studied (x) over 2 weeks and test score (y) at the end of the 2 weeks. The table is given below. Complete parts (a) through (d). X 11 16 12 18 7 16 16 79 y 91 85 82 75 86 85 Σχ= 120, Σy =661, Σxy = 9,793, Σx = 1,982, Σy = 54,801 a. Compute SST, SSR, and SSE, using the formulas, SST = Σy? - (Σyi)² /n, SSR = - SST= SSR= SSE = (Round to two decimal places as needed.) (Round to two decimal places as needed.) (Round to two decimal places as needed.) O 24 78 (Σxivi - (Σx) (Σvi) /n)² Ex² - (Ex)²/n b. Compute the coefficient of determination, r². 2= (Round to four decimal places as needed.) c. Determine the percentage of variation in the observed values of the response variable explained by the regression, and interpret your answer. % (Round to two decimal places as needed.) d. State how useful the regression equation appears to be for making predictions. Choose the correct answer below. Moderate to high usefulness Low usefulness and SSE = SST - SSR.
An instructor asked a random sample of eight students to record their study times at the beginning of a course. She then made a table for total hours studied (x) over 2 weeks and test score (y) at the end of the 2 weeks. The table is given below. Complete parts (a) through (d). X 11 16 12 18 7 16 16 79 y 91 85 82 75 86 85 Σχ= 120, Σy =661, Σxy = 9,793, Σx = 1,982, Σy = 54,801 a. Compute SST, SSR, and SSE, using the formulas, SST = Σy? - (Σyi)² /n, SSR = - SST= SSR= SSE = (Round to two decimal places as needed.) (Round to two decimal places as needed.) (Round to two decimal places as needed.) O 24 78 (Σxivi - (Σx) (Σvi) /n)² Ex² - (Ex)²/n b. Compute the coefficient of determination, r². 2= (Round to four decimal places as needed.) c. Determine the percentage of variation in the observed values of the response variable explained by the regression, and interpret your answer. % (Round to two decimal places as needed.) d. State how useful the regression equation appears to be for making predictions. Choose the correct answer below. Moderate to high usefulness Low usefulness and SSE = SST - SSR.