What radian measure is equivalent to 160 degrees
a.4pi/9
b.9pi/4
c.8pi/9
d.9pi/8

What is the quadric regression equation that fits these data

What is the missing step in this proof ?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed