| Exam Board | OCR |
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| Module | H240/02 (Pure Mathematics and Statistics) |
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| Topic | Hypothesis test of a normal distribution |
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10 In the past, the time spent in minutes, by customers in a certain library had mean 32.5 and standard deviation 8.2.
Following a change of layout in the library, the mean time spent in the library by a random sample of 50 customers is found to be 34.5 minutes.
Assuming that the standard deviation remains at 8.2 , test at the \(5 \%\) significance level whether the mean time spent by customers in the library has changed.