Date | May 2021 | Marks available | 2 | Reference code | 21M.1.AHL.TZ2.10 |
Level | Additional Higher Level | Paper | Paper 1 | Time zone | Time zone 2 |
Command term | Determine | Question number | 10 | Adapted from | N/A |
Question
A manufacturer of chocolates produces them in individual packets, claiming to have an average of chocolates per packet.
Talha bought of these packets in order to check the manufacturer’s claim.
Given that the number of individual chocolates is , Talha found that, from his packets, and .
Find an unbiased estimate for the mean number of chocolates per packet.
Use the formula to determine an unbiased estimate for the variance of the number of chocolates per packet.
Find a confidence interval for . You may assume that all conditions for a confidence interval have been met.
Suggest, with justification, a valid conclusion that Talha could make.
Markscheme
A1
[1 mark]
(M1)
A1
[2 marks]
A2
[2 marks]
is outside the confidence interval and therefore Talha would suggest that the manufacturer’s claim is incorrect R1
Note: The conclusion must refer back to the original claim.
Allow use of a two sided -test giving a -value rounding to and therefore Talha would suggest that the manufacturer’s claims in incorrect.
[1 mark]