A company advertised phone batteries with a mean standby time of 235 hours. A phone shop manager feels that the batteries have a standby time of less than 235 hours. The manager conducts an experiment and collects the following summary statistics:
n=200∑x=46313∑x2=10861255 n = 200 \quad \sum x = 46313 \quad \sum x^2 = 10861255 n=200∑x=46313∑x2=10861255Find the mean and standard deviation of the sample.
Carry out a hypothesis test to test the manager's claim at the 1% significance level. State your assumptions clearly.
