bac-s-maths 2025 Q1A

bac-s-maths · France · bac-spe-maths__amerique-nord_j2 Binomial Distribution Compute Exact Binomial Probability
In basketball, it is possible to score baskets worth one point, two points or three points.
The coach of a basketball team decides to study the success statistics of his players' shots. He observes that during training, when Victor attempts a three-point shot, he succeeds with a probability of 0.32. During a training session, Victor makes a series of 15 three-point shots. We assume that these shots are independent.
Let $N$ be the random variable giving the number of baskets scored. The results of the requested probabilities should be, if necessary, rounded to the nearest thousandth.
  1. We admit that the random variable $N$ follows a binomial distribution. Specify its parameters.
  2. Calculate the probability that Victor succeeds in exactly 4 baskets during this series.
  3. Determine the probability that Victor succeeds in at most 6 baskets during this series.
  4. Determine the expected value of the random variable $N$.
  5. Let $T$ be the random variable giving the number of points scored after this series of shots. a. Express $T$ as a function of $N$. b. Deduce the expected value of the random variable $T$. Give an interpretation of this value in the context of the exercise. c. Calculate $P ( 12 \leqslant T \leqslant 18 )$.
In basketball, it is possible to score baskets worth one point, two points or three points.

The coach of a basketball team decides to study the success statistics of his players' shots. He observes that during training, when Victor attempts a three-point shot, he succeeds with a probability of 0.32.
During a training session, Victor makes a series of 15 three-point shots. We assume that these shots are independent.

Let $N$ be the random variable giving the number of baskets scored.
The results of the requested probabilities should be, if necessary, rounded to the nearest thousandth.

\begin{enumerate}
  \item We admit that the random variable $N$ follows a binomial distribution. Specify its parameters.
  \item Calculate the probability that Victor succeeds in exactly 4 baskets during this series.
  \item Determine the probability that Victor succeeds in at most 6 baskets during this series.
  \item Determine the expected value of the random variable $N$.
  \item Let $T$ be the random variable giving the number of points scored after this series of shots.\\
a. Express $T$ as a function of $N$.\\
b. Deduce the expected value of the random variable $T$. Give an interpretation of this value in the context of the exercise.\\
c. Calculate $P ( 12 \leqslant T \leqslant 18 )$.
\end{enumerate}