bac-s-maths 2023 QExercise 4

bac-s-maths · France · bac-spe-maths__centres-etrangers_j2 Discrete Probability Distributions Expectation and Variance from Context-Based Random Variables
A production company is considering whether to schedule a television game show. This game brings together four candidates and takes place in two phases:
  • The first phase is a qualification phase. This phase depends only on chance. For each candidate, the probability of qualifying is 0.6.
  • The second phase is a competition between the qualified candidates. It only takes place if at least two candidates are qualified. Its duration depends on the number of qualified candidates as indicated in the table below (when there is no second phase, its duration is considered to be zero).

\begin{tabular}{ l } Number of candidates qualified
for the second phase
& 0 & 1 & 2 & 3 & 4 \hline
Duration of the second phase in
minutes
& 0 & 0 & 5 & 9 & 11 \hline \end{tabular}
For the company to decide to retain this game, the following two conditions must be verified: Condition no. 1: The second phase must take place in at least 80\% of cases. Condition no. 2: The average duration of the second phase must not exceed 6 minutes. Can the game be retained?
A production company is considering whether to schedule a television game show. This game brings together four candidates and takes place in two phases:
\begin{itemize}
  \item The first phase is a qualification phase. This phase depends only on chance. For each candidate, the probability of qualifying is 0.6.
  \item The second phase is a competition between the qualified candidates. It only takes place if at least two candidates are qualified. Its duration depends on the number of qualified candidates as indicated in the table below (when there is no second phase, its duration is considered to be zero).
\end{itemize}

\begin{center}
\begin{tabular}{ | l | l | l | l | l | c | }
\hline
\begin{tabular}{ l }
Number of candidates qualified \\
for the second phase \\
\end{tabular} & 0 & 1 & 2 & 3 & 4 \\
\hline
\begin{tabular}{ l }
Duration of the second phase in \\
minutes \\
\end{tabular} & 0 & 0 & 5 & 9 & 11 \\
\hline
\end{tabular}
\end{center}

For the company to decide to retain this game, the following two conditions must be verified:\\
Condition no. 1: The second phase must take place in at least 80\% of cases.\\
Condition no. 2: The average duration of the second phase must not exceed 6 minutes.\\
Can the game be retained?