The Foley Products Company has designed a new blend of concrete they believe will be twice as strong as their current high quality concrete. This new blend of concrete is believed to produce batches with a population mean strength of 15,000 psi and a population standard deviation of 2,000 psi. To validate this belief, they collect a random sample of 49 concrete batches out of all the batches produced at their plant in a particular week. The mean strength of the random sample of 49 concrete batches is measured to be 14,731 psi. Select the correct description of the population in this study.