Why do we use the standard uncertainty in the mean to quantify the uncertainty in the mean of a data set, but we use the standard deviation to quantify the uncertainty in individual measurements?.

What is (28 + 7 + 6 + 3) x 1/2 show your work

In right ∆abc shown below, the midpoint of hypotenuse ac is located at d and segment bd is drawn.if ab = 12 and bc = 16, then explain why bd = 10. hint: consider what you know about the diagonals of a rectangle.

If i have 20$ and i gave 5$ away how much i got