Transcript text: 3.4 Contingency Tables
Use the following information to answer the next four exercises. Table 3.15 shows a random sample of musicians and hor they learned to play their instruments.
\begin{tabular}{|l|l|l|l|l|}
\hline Gender & Self-taught & Studied in School & Private Instruction & Total \\
\hline Female & 12 & 38 & 22 & 72 \\
\hline Male & 19 & 24 & 15 & 58 \\
\hline Total & 31 & 62 & 37 & 130 \\
\hline
\end{tabular}
Table 3.15
54. Find $P$ (musician is a female).
Solution
Solution Steps
To find the probability that a randomly selected musician is female, we need to divide the total number of female musicians by the total number of musicians. This will give us the probability of selecting a female musician from the sample.
Step 1: Identify the Total Number of Female Musicians
The total number of female musicians is given as 72.
Step 2: Identify the Total Number of Musicians
The total number of musicians, including both male and female, is given as 130.
Step 3: Calculate the Probability
The probability \( P \) that a randomly selected musician is female is calculated by dividing the total number of female musicians by the total number of musicians:
\[
P(\text{female}) = \frac{\text{Number of Female Musicians}}{\text{Total Number of Musicians}} = \frac{72}{130}
\]
Step 4: Simplify the Fraction
Simplifying the fraction \(\frac{72}{130}\) gives:
\[
P(\text{female}) = \frac{36}{65}
\]
Step 5: Convert to Decimal
Converting the simplified fraction to a decimal:
\[
P(\text{female}) \approx 0.5538
\]
Final Answer
The probability that a randomly selected musician is female is \(\boxed{0.5538}\).