12. Review from Unit 1: Lesson 1

The table below summarizes the condition and type for a group of car transmissions. If a transmission from this group is selected at random, what is the probability of selecting a transmission in good condition, given that it is an automatic transmission?

\begin{tabular}{|l|c|c|r|}
\hline
\multirow{2}{*}{Condition} & \multicolumn{3}{|c|}{Type of transmission} \\
\cline{2-4}
& Automatic & Manual & Total \\
\hline
Excellent & 248 & 161 & 409 \\
\hline
Very good & 152 & 97 & 249 \\
\hline
Good & 108 & 162 & 270 \\
\hline
Satisfactory & 56 & 88 & 144 \\
\hline
Poor & 36 & 98 & 134 \\
\hline
Total & 600 & 606 & 1,206 \\
\hline
\end{tabular}



Answer :

To determine the probability of selecting a transmission in good condition, given that it is an automatic transmission, we need to follow these steps:

1. Identify the total number of automatic transmissions:
- The table summarizes the number of automatic transmissions for each condition. To find the total number of automatic transmissions, we sum these values:
[tex]\[ \text{Total automatic transmissions} = 248 + 152 + 108 + 56 + 36 = 600 \][/tex]

2. Identify the number of automatic transmissions in good condition:
- From the table, the number of automatic transmissions in good condition is given as 108.

3. Calculate the probability:
- The probability of an event is given by the ratio of the favorable outcomes to the total possible outcomes.
- Here, the favorable outcomes are the automatic transmissions in good condition, and the total possible outcomes are the total number of automatic transmissions.
[tex]\[ \text{Probability} = \frac{\text{Number of automatic transmissions in good condition}}{\text{Total number of automatic transmissions}} \][/tex]
- Substituting the values we identified:
[tex]\[ \text{Probability} = \frac{108}{600} \][/tex]

4. Simplify the fraction:
- To simplify the fraction, we divide the numerator and the denominator by their greatest common divisor (GCD). The GCD of 108 and 600 is 12:
[tex]\[ \frac{108 \div 12}{600 \div 12} = \frac{9}{50} = 0.18 \][/tex]

Thus, the probability of selecting a transmission in good condition, given that it is an automatic transmission, is [tex]\( 0.18 \)[/tex] or 18%.

By following these steps, we see that:

- The total number of automatic transmissions is 600.
- The number of automatic transmissions in good condition is 108.
- The probability of selecting a transmission in good condition, given that it is an automatic transmission, is 0.18 or 18%.