A leading company chemically treats its product before packaging.The company monitors the weight of product per hour that each machine treats. A simple random sample of 25 one hour periods from one machine was taken. The results in kilos are shown below:
16591170841917218451175361859817253146241758916625110581663319718192191842117976179381680318830201092115115139199331821618523
(a) Can the company conclude that the mean kilo of product treated in one hour by this machine is more than 15,000? Use a 5% level of significance.
(b) What assumptions must be made for the test to be valid?