Question

The data set below shows the number of students in 12
math classrooms.
16,18,20,19,19,18,20,25,27,18,20,23
A. 18,20
B. 19,20
C. 19,22
D. 19
Best answer

Answer 1

To determine the best answer, we first need to calculate the mean (average), median, and mode of the data set, which may help us identify the central tendency.

**Data Set:**
16, 18, 20, 19, 19, 18, 20, 25, 27, 18, 20, 23

1. **Mean:**
\[
\text{Mean} = \frac{\text{Sum of all values}}{\text{Number of values}} = \frac{16 + 18 + 20 + 19 + 19 + 18 + 20 + 25 + 27 + 18 + 20 + 23}{12} = \frac{ 16 + 18 + 20 + 19 + 19 + 18 + 20 + 25 + 27 + 18 + 20 + 23 }{12} = \frac{ 20 + 19 + 20 + 25 + 27 + 20 + 20 + 23 }{12} = \frac{ 23 + 23 + 25 + 20 + 19 + 19}{12} \approx 20
\]

2. **Median:**
To find the median, we need to arrange the data set in ascending order:
16, 18, 18, 18, 19, 19, 20, 20, 20, 23, 25, 27

Since there are 12 values (even number), we take the average of the 6th and 7th values.
\[
\text{Median} = \frac{19 + 20}{2} = 19.5
\]

3. **Mode:**
The mode is the value that appears most frequently.
From the data set, we have:
- 18 appears 3 times
- 19 appears 2 times
- 20 appears 3 times

So, the modes are 18 and 20.

Now let's analyze the options provided:

A. 18, 20
B. 19, 20
C. 19, 22
D. 19

Based on the calculations, the best answer considering the measures of central tendency (mean, median, and mode) is:

**A. 18, 20**

This option reflects the modes of the data set.