Theoretical Probability

A group of students was surveyed in a middle school class. They were asked how many hours they work on math homework each week. The results from the survey were recorded:

\begin{tabular}{|c|c|}
\hline
Number of Hours & Total Number of Students \\
\hline
0 & 1 \\
\hline
1 & 3 \\
\hline
2 & 3 \\
\hline
3 & 10 \\
\hline
4 & 9 \\
\hline
5 & 6 \\
\hline
6 & 3 \\
\hline
\end{tabular}

Determine the probability that a student studied for exactly 5 hours. Round to the nearest hundredth.



Answer :

To determine the probability that a student studied for exactly 5 hours, we need to follow these steps:

1. Find the Total Number of Students Surveyed:
To get the total number of students surveyed, we sum the number of students in each category.

[tex]\[ \begin{aligned} 1 + 3 + 3 + 10 + 9 + 6 + 3 = 35 \end{aligned} \][/tex]

So, the total number of students surveyed is 35.

2. Identify the Number of Students who Studied for Exactly 5 Hours:
From the survey table, we can see that the number of students who studied for exactly 5 hours is 6.

3. Calculate the Probability:
The probability that a randomly selected student studied for exactly 5 hours is given by the ratio of the number of students who studied for 5 hours to the total number of students surveyed.

[tex]\[ \begin{aligned} \text{Probability} &= \frac{\text{Number of students who studied for 5 hours}}{\text{Total number of students}} \\ &= \frac{6}{35} \end{aligned} \][/tex]

4. Rounding to the Nearest Hundredth:
To get the probability rounded to the nearest hundredth, we calculate:

[tex]\[ \frac{6}{35} \approx 0.171428571 \][/tex]

Rounded to the nearest hundredth, this is 0.17.

So, the probability that a student studied for exactly 5 hours is [tex]\( 0.17 \)[/tex].