X + 2/3 = -5/6 solving equations

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

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Use the distance formula to find the distance between (-3,5) and (3,1)