College

The table below shows the times taken for a group of athletes to finish a 200 m race.

Work out the percentage of the athletes who took more than 26 seconds to finish the race.

[tex]\[
\begin{tabular}{|c|c|}
\hline
\text{Time, } t(s) & \text{Frequency} \\
\hline
22 < t \leq 24 & 3 \\
\hline
24 < t \leq 26 & 5 \\
\hline
26 < t \leq 28 & 8 \\
\hline
28 < t \leq 30 & 9 \\
\hline
\end{tabular}
\][/tex]

Answer :

To find the percentage of athletes who took more than 26 seconds to finish the race, follow these steps:

1. Identify the frequency of athletes in each time interval:
- For the time interval [tex]\(22 < t \leq 24\)[/tex], there are 3 athletes.
- For the time interval [tex]\(24 < t \leq 26\)[/tex], there are 5 athletes.
- For the time interval [tex]\(26 < t \leq 28\)[/tex], there are 8 athletes.
- For the time interval [tex]\(28 < t \leq 30\)[/tex], there are 9 athletes.

2. Calculate the total number of athletes:
- Add all the frequencies together: [tex]\(3 + 5 + 8 + 9 = 25\)[/tex]. So, there are 25 athletes in total.

3. Determine the number of athletes who took more than 26 seconds:
- This includes athletes in the time intervals [tex]\(26 < t \leq 28\)[/tex] and [tex]\(28 < t \leq 30\)[/tex].
- Add these frequencies: [tex]\(8 + 9 = 17\)[/tex]. There are 17 athletes who took more than 26 seconds.

4. Calculate the percentage of these athletes:
- Use the formula for percentage: [tex]\(\left(\frac{\text{Number of athletes taking more than 26 s}}{\text{Total number of athletes}}\right) \times 100\)[/tex].
- Substitute the values: [tex]\(\left(\frac{17}{25}\right) \times 100 = 68\%\)[/tex].

Thus, 68% of the athletes took more than 26 seconds to finish the race.