Questions: Find the probability of exactly three successes in eight trials of a binomial experiment in which the probability of success is 45%.
n=8 p=0.45 q=0.55 k=3
Enter values into the formula.
P(k)=nCk(p)^k(q)^(n-k)
P(3)=8C3(0.45)^3(0.55)^5
Transcript text: SKIp
Find the probability of exactly three successes in eight trials of a binomial experiment in which the probability of success is $45 \%$.
\[
\mathrm{n}=8 \quad \mathrm{p}=0.45 \quad \mathrm{q}=0.55 \quad \mathrm{k}=3
\]
Enter values into the formula.
\[
\begin{array}{r}
P(k)={ }_{n} C_{k}(p)^{k}(q)^{n-k} \\
P(3)={ }_{8} C_{[?]}(\square)(\square)
\end{array}
\]
Solution
Solution Steps
Step 1: Define the Problem
We are tasked with finding the probability of exactly \( k = 3 \) successes in \( n = 8 \) trials of a binomial experiment, where the probability of success on each trial is \( p = 0.45 \). The probability of failure is given by \( q = 1 - p = 0.55 \).
Step 2: Apply the Binomial Probability Formula
The probability of exactly \( k \) successes in \( n \) trials is given by the formula:
\[
P(k) = {n \choose k} p^k q^{n-k}
\]
Substituting the known values:
\[
P(3) = {8 \choose 3} (0.45)^3 (0.55)^{8-3}
\]
Step 3: Calculate the Probability
Using the binomial probability mass function, we find:
\[
P(3) \approx 0.2568
\]
Final Answer
The probability of exactly 3 successes in 8 trials with a success probability of \( 0.45 \) is approximately:
\[
\boxed{0.2568}
\]