A sample of n=8 scores has a mean of m=12. What is the value of ∑x for this sample
Answer: We are given the mean of 8 scores is 12.
We are required to find the sum of these 8 observation's, 
We know that:

We are given:




Hence, sum of 8 observation's, 
A matrix is diagonal if

In other words, you want non-zero elements only when the indices of the row and the column are the same: the first element of the first row must be non zero, the second element of the second row must be non-zero, and so on. All other elements must be zero.
1) 32w -40
2) -275
Lmk if it helped you
Because 4.7 is the "abbreviation" for 4.70 also 4.7 is the simplified version of 4.70 kind of like a fraction you 4 70/100 simplified is 4 7/10 or 4.7.