Answer:
Option B. 7.5 is the correct answer
Explanation:
Let us define standard deviation first.
Standard deviation is the square root of variance. Standard Deviation tells us that how far are the values in a data set from the mean.
Now, if a constant is subtracted from all values of a dataset, the standard deviation remains the same. Only the origin or mean of the data changes by subtracting a constant from whole data set.
Given that the standard deviation of dataset is 7.5
Subtracting 2 from each value of dataset will not change the standard deviation as 2 is a constant.
Hence,
Option B. 7.5 is the correct answer