When a random sample is selected from a population, the sample mean is not expected to be exactly equal to the population mean. On average, the distance between the sample mean and the population mean is predicted bya. the standard error
b. the expected value
c. the mean of the population
d. the standard deviation of the population

You’re ordering more thread for blue jeans co. you usually purchase from ted’s threads, which sells 12 thread spools for $27. you recently received a notice from wade's wares that says you can buy thread from them for $2.30 each for the first 2 dozen and $2 a spool thereafter. you need to order 5 dozen spools. what percentage can you save by going with wade’s wares?