Find each mean.
56; 59; 51; 63; 68; 57; 52
146; 153; 117; 148
200; 141; 257; 199
912; 738; 420
15; 9; 7; 6; 8; 11; 4; 9; 6; 7
19; 27; 34; 18; 23
56; 59; 51; 63; 68; 57; 52
146; 153; 117; 148
200; 141; 257; 199
912; 738; 420
15; 9; 7; 6; 8; 11; 4; 9; 6; 7
19; 27; 34; 18; 23