Answer:
1.) 1.2, 2.3, 4.5, 2.0, 1.5, 1.6, 5.0, 5.5, 5.7
rearrange: 1.2, 1.5, 1.6, 2.0, 2.3, 4.5, 5.0, 5.5, 5.7
mean: 3.25
median: 2.3
mode: no mode
2.) 10, 12, 14, 10, 15, 18, 20, 20, 21
rearrange: 10, 10, 12, 14, 15, 18, 20, 20, 21
mean: 15.55
median: 15
mode: 10 and 20
3.) 85, 84, 85, 89, 87, 88, 85, 82, 89, 88, 86, 87, 82, 83, 84, 80
rearrange:80,82,82,83,84,84,85,85,85,86,87,87,88,88,89,89
mean: 85.25
median: 85
mode: 85