WJEC Further Unit 2 2024 June — Question 1 14 marks

Exam BoardWJEC
ModuleFurther Unit 2 (Further Unit 2)
Year2024
SessionJune
Marks14
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSum of Poisson processes
TypeRescale rate then sum Poissons
DifficultyStandard +0.3 This is a straightforward application of standard Poisson distribution techniques (scaling rates, adding independent Poisson processes, memoryless property, and normal approximation to binomial). All parts follow textbook procedures with no novel problem-solving required, making it slightly easier than average for Further Maths statistics.
Spec5.02i Poisson distribution: random events model5.02j Poisson formula: P(X=x) = e^(-lambda)*lambda^x/x!5.02k Calculate Poisson probabilities5.03a Continuous random variables: pdf and cdf

  1. Dave and Llinos like to go fishing. When they go fishing, on average, Dave catches 4.3 fish per day and Llinos catches 3.8 fish per day. A day of fishing is assumed to be 8 hours.
    1. (i) Calculate the probability that they will catch fewer than 2 fish in total on a randomly selected half-day of fishing.
      (ii) Justify any distribution you have used in answering (a)(i).
    2. On a randomly selected day, Dave starts fishing at 7 am. Given that Dave has not caught a fish by 11 am,
      1. find the expected time he catches his first fish,
      2. calculate the probability that he will not catch a fish by 3 pm .
    3. On average, only \(2 \%\) of the fish that Llinos catches are trout. Over the course of a year, she catches 950 fish. Calculate the probability that at least 30 of these fish are trout. [3]
      [0pt] she catches 950 fish. Calculate the probability that at least 30 of these fish are trout. [3]
    4. State, with a reason, a distribution, including any parameters, that could approximate the distribution used in part (c).
    PLEASE DO NOT WRITE ON THIS PAGE

Question 1:
AnswerMarks
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Question 1:
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\begin{enumerate}
  \item Dave and Llinos like to go fishing. When they go fishing, on average, Dave catches 4.3 fish per day and Llinos catches 3.8 fish per day. A day of fishing is assumed to be 8 hours.\\
(a) (i) Calculate the probability that they will catch fewer than 2 fish in total on a randomly selected half-day of fishing.\\
(ii) Justify any distribution you have used in answering (a)(i).\\

(b) On a randomly selected day, Dave starts fishing at 7 am. Given that Dave has not caught a fish by 11 am,\\
(i) find the expected time he catches his first fish,\\
(ii) calculate the probability that he will not catch a fish by 3 pm .\\

(c) On average, only $2 \%$ of the fish that Llinos catches are trout. Over the course of a year, she catches 950 fish. Calculate the probability that at least 30 of these fish are trout. [3]\\[0pt]
she catches 950 fish. Calculate the probability that at least 30 of these fish are trout. [3]\\

(d) State, with a reason, a distribution, including any parameters, that could approximate the distribution used in part (c).\\

\end{enumerate}

PLEASE DO NOT WRITE ON THIS PAGE\\

\hfill \mbox{\textit{WJEC Further Unit 2 2024 Q1 [14]}}