Hypothesis Test for one population Mean (t-Test)
An Inventor has developed a new, energy-efficient lawn mower engine. He claims that the engine will run continuously for 5 hours ( 300 minutes) on a single gallon of regular gasoline. from his stock of 2000 engines, the inventor selects a simple random sample of 50 engines for testing. the engines run for an sample average of 295 minutes, with a sample standard deviation of 20 minutes. Does the data here provide evidence that the mean run time is not 300 minutes. Use a 0.05 level of significance.