Which Statement is true about figure DEF

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?

Evaluate the expression for the given value of the variable. | ? 4 b ? 8 | + ? ? ? 1 ? b 2 ? ? + 2 b 3 -4b-8+-1-b2+2b3 ; b = ? 2 b=-2