(a) Difference is as follows:

9.756 – 6.28

Therefore, difference is 3.476

(b) Difference is as follows:

21.05 – 15.27

Therefore, difference is 5.78

(c) Difference is as follows:

18.5 – 6.79

Therefore, difference is 11.71

(ds) Difference is as follows:

11.6 – 9.847

Therefore, difference is 1.753