Question 1043553
Let
S = sum of the nine test scores


Dividing the sum (S) by 9 gives the mean of 61, so,
S/9 = 61


Solve for S. Do this by multiplying both sides by 9
S/9 = 61
(S/9)*9 = 61*9
S = 549


So we know that the sum of the nine scores is 549. We don't know the actual individual scores. However, we can determine the new mean.


Add 71 to the sum of the other scores (549) to get
71+549 = 620


Now divide this by 10 to compute the mean of the 10 scores
620/10 = 62


So the mean has gone from 61 to 62


The final answer is 62