Rose 40%
original=100%, now it is 140%
140% of original=now
140% of orignal=350
1.4 of original=350
divide both sides by 1.4
original=250
answer is C
other way
350/140=x/100
35/14=x/100
times both sides by 1400
3500=14x
divie both sides by 14
250=x
C is answer
To compute the mean, you simply have to sum all the elments in the data set and the divide the sum by the number of elements:

To compute the variance, we first need to compute the distance of each element from the mean. To do so, we build a "parallel" dataset, given by the difference of every value and the mean:


Now we need those difference squared:

The variance is the mean of this new vector, so

Finally, the standard deviation is simply the square root of the variance, so you have

Answer: 6 1/2
Step-by-step explanation:
3(2)+17-28
multiply 3(2)=6
6+17-28
work left to right
6+17=23
23-28=-5