SPS SPS FM Statistics 2021 June — Question 6 6 marks

Exam BoardSPS
ModuleSPS FM Statistics (SPS FM Statistics)
Year2021
SessionJune
Marks6
TopicConditional Probability
TypeStandard Bayes with discrete events
DifficultyStandard +0.3 This is a straightforward Bayes' theorem application with clearly stated probabilities and frequencies. Students need to calculate P(Volt|Lost) using the law of total probability, requiring only standard conditional probability formulas with no conceptual tricks. The arithmetic is manageable and the context is typical for A-level statistics.
Spec2.03c Conditional probability: using diagrams/tables2.03d Calculate conditional probability: from first principles

Only two airlines fly daily into an airport. AMP Air has 70 flights per day and Volt Air has 65 flights per day. Passengers flying with AMP Air have an 18% probability of losing their luggage and passengers flying with Volt Air have a 23% probability of losing their luggage. You overhear a passenger in the airport complaining about her luggage being lost. Find the exact probability that she travelled with Volt Air, giving your answer as a rational number. [6]

Only two airlines fly daily into an airport.

AMP Air has 70 flights per day and Volt Air has 65 flights per day.

Passengers flying with AMP Air have an 18% probability of losing their luggage and passengers flying with Volt Air have a 23% probability of losing their luggage.

You overhear a passenger in the airport complaining about her luggage being lost.

Find the exact probability that she travelled with Volt Air, giving your answer as a rational number.
[6]

\hfill \mbox{\textit{SPS SPS FM Statistics 2021 Q6 [6]}}