Identify which numbers are written correctly in scientific notation and which are not

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Which functions shave a maximum and are transformed to the left and down of the parent function ,check all that apply f(x) = x2? p(x) =14 (x+7)2 + 1

What is r i 4.5+10r=-6.5 with work pls