Question

The accompanying table contains two samples that were collected as matched pairs. Complete parts a and b below.

Pair	Sample 1	Sample 2
1	10	4
2	6	7
3	4	6
4	8	3
5	11	5
6	7	9
7	8	5
8	7	5

A.

Construct a 90?% confidence interval to estimate difference in means between the populations from which Sample 1 and 2 were drawn.

UCL d-overbar	= ??
LCL d-overbar	= ??

B . What conclusions can be made?

The interval "does not include OR does include" ?zero, so there "is OR is not" enough evidence to conclude that there is a difference in means between the populations from which Sample 1 and 2 were drawn.

Answer 1

A)

t value at 90% = 1.8946

Sample 1 Sample2 dbar

10 4 6

6 7 -1

4 6 -2

8 3 5

11 5 6

7 9 -2

8 5 3

7 5 2

dbar = ?(sample1) - ?(sample2)

= 7.625 - 5.5

= 1.7

s(dbar) = 2.1998 - 1.8516

= 3.1640

SE = s(dbar)/sqrt(n) = 1.1187

CI = dbar +/- t *SE

= 1.7 +/- 1.8946 *1.1187

= (-0.4194 , 3.8194 )

B)

The interval "does include" ?zero, so there "is" enough evidence to conclude that there is a difference in means between the populations from which Sample 1 and 2 were drawn.