To find the mean (average) of the given numbers, follow these steps:

1. List the numbers: The numbers are: 1.2, 1.4, 1.5, 1.7, and 2.

2. Add all the numbers together: $1.2 + 1.4 + 1.5 + 1.7 + 2 = 7.8$

3. Count the number of numbers: There are 5 numbers.

4. Divide the sum by the count: $\text{Mean} = \frac{7.8}{5} = 1.56$

Thus, the mean of these numbers is 1.56.

How to check your work:

• Recalculate the sum: Make sure the total is still 7.8 by adding the numbers again.
• Verify the division: Divide the sum (7.8) by the count (5) to confirm you get 1.56 again.

Would you like more details or have any questions?

Here are 5 related questions for further practice:

1. What is the median of the numbers 1.2, 1.4, 1.5, 1.7, and 2?
2. What is the mode of the same set of numbers?
3. How would the mean change if you added another number, say 1.9?
4. How do you calculate the mean of a set of numbers with negative values?
5. What is the difference between the mean and the median?

Tip: Always double-check your division by multiplying the mean by the number of values to see if you get the original sum.