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.
355 exam-style questions on OCR (MEI) A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 Process and language of hypothesis testing, 2.5.2 When to apply 1-tail and 2-tail tests, 2.5.3 Significance level and incorrect rejection, 2.5.4 Null and alternative hypotheses (binomial), 2.5.5 Conduct a binomial hypothesis test, 2.5.6 Critical and acceptance regions (binomial), 2.5.7 Distribution of the sample mean (A-level only), 2.5.8 Hypothesis test for a single mean (A-level only), 2.5.9 Critical and acceptance regions (mean) (A-level only), 2.5.10 Correlation as closeness to a straight line (A-level only), 2.5.11 Inference using a correlation coefficient (A-level only), and 2.5 Statistical Hypothesis Testing. Each one has a worked solution and a mark scheme showing where the marks go.