CAIE S2 2015 November — Question 6

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2015
SessionNovember
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TopicLinear combinations of normal random variables

6 The weights, in kilograms, of men and women have the distributions \(\mathrm { N } \left( 78,7 ^ { 2 } \right)\) and \(\mathrm { N } \left( 66,5 ^ { 2 } \right)\) respectively.
  1. The maximum load that a certain cable car can carry safely is 1200 kg . If 9 randomly chosen men and 7 randomly chosen women enter the cable car, find the probability that the cable car can operate safely.
  2. Find the probability that a randomly chosen woman weighs more than a randomly chosen man.

6 The weights, in kilograms, of men and women have the distributions $\mathrm { N } \left( 78,7 ^ { 2 } \right)$ and $\mathrm { N } \left( 66,5 ^ { 2 } \right)$ respectively.\\
(i) The maximum load that a certain cable car can carry safely is 1200 kg . If 9 randomly chosen men and 7 randomly chosen women enter the cable car, find the probability that the cable car can operate safely.\\
(ii) Find the probability that a randomly chosen woman weighs more than a randomly chosen man.

\hfill \mbox{\textit{CAIE S2 2015 Q6}}