To find the mean of the values in a stem-and-leaf plot, we need to:

1. Extract the values from the plot.
2. Add them together.
3. Divide by the number of values to calculate the mean.

Let's use the stem-and-leaf plot and follow these steps:

Example Stem-and-Leaf Plot:

Stem 1: 12, 14, 15, 17
Stem 2: 28, 29
Stem 3: 30, 31, 34, 35
Stem 4: 40, 41, 44, 45
Stem 5: 50
Stem 6: 69

Step 1: List the data:

The data values from the stem-and-leaf plot are: 12, 14, 15, 17, 28, 29, 30, 31, 34, 35, 40, 41, 44, 45, 50, 69

Step 2: Add the values:

$12 + 14 + 15 + 17 + 28 + 29 + 30 + 31 + 34 + 35 + 40 + 41 + 44 + 45 + 50 + 69 = 480$

Step 3: Count the number of values:

There are 16 values in the data set.

Step 4: Calculate the mean:

$\text{Mean} = \frac{\text{Sum of values}}{\text{Number of values}} = \frac{480}{16} = 30$

Thus, the mean of the values in the stem-and-leaf plot is 30.

Let me know if you need more details or have any further questions!

Here are some related questions:

1. How do you find the median of a data set from a stem-and-leaf plot?
2. What is the difference between the mean and the mode?
3. How do you calculate the range of a data set from a stem-and-leaf plot?
4. How can you find the mode and median of a data set simultaneously?
5. What is the significance of outliers in calculating the mean?

Tip: When calculating the mean, it's always important to add the values correctly and then divide by the number of values to ensure an accurate result!