Find the mean, median, and mode(s) of the data in the following stem-and-leaf plot. The leaf represents the ones digit.

0|4
1|55
2|4578
3|2

1 answer

To find the mean, median, and mode(s) of the data represented in the stem-and-leaf plot, we first need to reconstruct the actual dataset based on the plot.

The stem-and-leaf plot is given as follows:

0 | 4
1 | 5 5
2 | 4 5 7 8
3 | 2

From this plot, we can list the numbers:

  • From the stem 0, the leaf 4 corresponds to the number 4.
  • From the stem 1, the leaves 5 5 correspond to the numbers 15 and 15.
  • From the stem 2, the leaves 4 5 7 8 correspond to the numbers 24, 25, 27, and 28.
  • From the stem 3, the leaf 2 corresponds to the number 32.

Putting this all together, our dataset is: \[ 4, 15, 15, 24, 25, 27, 28, 32 \]

Step 1: Calculate the mean

The mean is calculated by taking the sum of all data points and dividing by the number of data points.

Sum of the data: \[ 4 + 15 + 15 + 24 + 25 + 27 + 28 + 32 = 150 \]

Number of data points: \[ 8 \]

Mean: \[ \text{Mean} = \frac{150}{8} = 18.75 \]

Step 2: Calculate the median

To find the median, we need to arrange the data in ascending order (already in order): \[ 4, 15, 15, 24, 25, 27, 28, 32 \]

Since there are 8 data points (even number), the median will be the average of the 4th and 5th terms.

The 4th term is 24 and the 5th term is 25.

Median: \[ \text{Median} = \frac{24 + 25}{2} = \frac{49}{2} = 24.5 \]

Step 3: Find the mode(s)

The mode is the number(s) that appear most frequently in the dataset.

From our dataset:

  • 4 appears 1 time
  • 15 appears 2 times
  • 24 appears 1 time
  • 25 appears 1 time
  • 27 appears 1 time
  • 28 appears 1 time
  • 32 appears 1 time

The number 15 appears most frequently (2 times).

Thus, the mode is: \[ \text{Mode} = 15 \]

Summary of Results

  • Mean: 18.75
  • Median: 24.5
  • Mode: 15