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.
Practise Edexcel A Level Maths The Normal Distribution with exam-style questions for A Level Maths. 100 questions covering The Normal Distribution, Finding Probabilities for Normal Distributions, The Inverse Normal Distribution Function, The Standard Normal Distribution, Finding the mean and standard deviation, Approximating a Binomial Distribution, and Hypothesis Testing with the Normal Distribution, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.