1.A psychologist was interested in the effect of Vitamin A deficiency on maze learning rats. A group of nine rats learned a simple maze. Next, these same rats were deprived of Vitamin A for six weeks and were then tested again on their ability to learn a second maze equal in difficulty to the first. The scores represent the number of maze errors made under the two treatment conditions. Perform an appropriate two-tailed test of the significance of the mean difference.

Pre-test

Post-test

17

13

18

23

19

18

10

19

22

22

21

26

15

18

18

13

19

29

a.(.5 pt) Hypothesis: H0:=

b.(.25 pt)df= 7

c.(.75 pt) t_crit= 2.365

d.(.25 pt) Mean difference = pretest 17.55 post 20.11 = -2.56

e.(1 pt) t_obs= 17.59

f.(0.5 pt) Experimental conclusion (Write out):

g.(0.5 pt) Find the 95% CI for this data: 15.03 to 20.15