Answer
Dataset D has a much larger spread and higher average value
Work Step by Step
Dataset C: 4.5,7.1,8.3,6.9
Dataset D:2.1,29.5,1.2,3.3
Mean C: Add all the numbers and divide by 4 :$\frac{4.5+7.1+8.3+6.9}{4}$=6.7
Mean D: Add all the numbers and divide by 4: $\frac{2.1+29.5+1.2+3.3}{4}$=9.025
Dataset D has the larger average.
Range C: The difference between the largest and smallest number: 8.3-4.5=3.8
Range D: The difference between the largest and smallest number:29.5-1.2=28.3.
Dataset D has the larger spread.
Set D has a higher average and a larger spread.