The number of cars in the yard is three times as high as the number of mopeds. the number of bicycles is twice as high as the number of cars. the total number of vehicles is 30. use the equation to solve the number of cars, mopeds and bicycles.

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Write an inequality and solve each problem.for exercises 11 and 12, interpret the solution.