Why are chemical properties harder to observe than physical properties?

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.)

How many times did thomas edison mess up the light bulb

What is the rate of 12 liters of water moving through a water hose in 4.0 minutes?