Paper 1 · normal distribution
A machine packs washing powder into packets that are normally distributed with mean 2 kg and standard deviation 0.039 kg. Find the proportion of packets that weigh more than 2.10 kg.
A0.26%
B0.52%
C1.05%
D10.00%
Explanation: z = (2.10-2)/0.039, which is about 2.56. P(Z > 2.56) = 1 - 0.9948 = 0.0052, i.e. about 0.52%.
Derived from ZIMSEC Statistics Paper 1, November 2022, Q2
