Explain the purpose of oxidation numbers?

Use the empirical rule. the mean speed of a sample of vehicles along a stretch of highway is 70 miles per hour, with a standard deviation of 4 miles per hour. estimate the percent of vehicles whose speeds are between 66 miles per hour and 74 miles per hour. (assume the data set has a bell-shaped distribution.)

An inclined plane wrapped around a metal shaft is a a. lever b. screw c. pulley d. wedge

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.