Comparing scales: In an experiment to determine whether there is a systematic difference between the weights obtained with two different scales, 10 rock specimens were weighed, in grams, on each scale. The following data were obtained:

Specimen Weight on Scale 1 Weight on Scale 2
1

12.35

12.51

2

15.08

14.99

3

9.00

9.10

4

11.55

11.47

5

24.36

24.35

6

9.88

10.00

7

15.36

15.55

8

7.05

7.04

9

13.39

13.57

Let μ1 represent the mean weight on Scale 1 and ud= μ1-μ2

Can you conclude that the mean weight on Scale 1 is less than the mean weight on Scale 2?

Use the a=0.10 level of significance.

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )