Answer:
1.9
Step by step answer
step1 finding the mean
(7+4+7+7+2+10+12+8+7+5)/10 = 6.9
step2 Difference between each data
Difference between 7 and 6.9 is 0.1
Difference between 4 and 6.9 is 2.9
Difference between 7 and 6.9 is 0.1
Difference between 7 and 6.9 is 0.1
Difference between 2 and 6.9 is 4.9
Difference between 10 and 6.9 is 3.1
Difference between 12 and 6.9 is 5.1
Difference between 8 and 6.9 is 1.1
Difference between 7 and 6.9 is 0.1
Difference between 5 and 6.9 is 1.9
step3 add all the Difference
0.1 + 2.9+0.1+0.1+4.9+3.1+5.1+1.1+1.9 = 19.4
step4 divde it by n
19.4/10 = 1.9
so the answer is 1.9