Can someone tell me if this is correct? I said neither is correct.

What is the effect on the graph of the parent function f(x) = x when f(x) is replaced with 3f(x)? a) shifts the line 3 units up b) shifts the line 3 units down c) increases the slope of the line by a factor of 3 d) decreases the slope of the line by a factor of 3

Factor. 8x2y2 – 4x2y – 12xy 4(8x2y2 – x – 12xy) 4(2xy – 4x2y – 12xy) 4x2y2(2xy – xy –3) 4xy(2xy – x – 3)

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