9231 P41 - Jun 2022 - Q5 - 9 marks
6706
Raman is researching the heights of male giraffes in a particular region. Raman assumes that the heights of male giraffes in this region are normally distributed. He takes a random sample of 8 male giraffes from the region and measures the height, in metres, of each giraffe. These heights are as follows.
| 5.2 | 5.8 | 4.9 | 6.1 | 5.5 | 5.9 | 5.4 | 5.6 |
(a) Find a 90% confidence interval for the population mean height of male giraffes in this region.
Raman claims that the population mean height of male giraffes in the region is less than 5.9 metres.
(b) Test at the 2.5% significance level whether this sample provides sufficient evidence to support Raman's claim.
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