Question

Listed below are the results from two different tests designed to measure achievement.

(x) test A	64	48	51	59	60	43	41	42	35	50	45
(y) test B	91	68	80	92	91	67	65	67	56	78	71

a. Plot the scatter diagram below. Label X and y axes. Do a rough sketch.

b. Find the value of the linear correlation coefficient r by the TI83 shortcut- state calculator screen name.

C. Test the claim of no linear relation by the ti83 p -value method, apha = 0.05

Claim:

Null Hypothesis:

Alternative Hypothesis:

Calculator Screen Name in Ti 183:

test statistics:

Pvalue/alpha conversion

decision:

Conclusion:

d. find the estimated equation of the regression line by Ti 83 shortcut.

e. plot the regression line on the scatter diagram in part a).

f. assuming a significant linear correlation, predict the score a student would get on Test B, given he got a 85 on test A.

g. what percentage of the total variation can be explained by the regression line?

Answer 1

a) scatter diagram as below :

e) Regression line on scatter diagram

f)

X=85

Y=10.5880 + 1.3188*85

= 122.686

g)

r^2 = 0.9745^2 = 0.94965

94.965 % of explained variation determined by the regression line