The problem asks for the rate of change between Sunday and Wednesday based on the number of voicemail messages on John's phone.

Here's how we can calculate that:

Step 1: Identify the number of voicemail messages on Sunday and Wednesday.

• Sunday: 12 messages
• Wednesday: 2 messages

Step 2: Calculate the rate of change.

Rate of change is calculated by the formula:

$\text{Rate of change} = \frac{\text{Change in voicemail messages}}{\text{Change in days}}$

Change in voicemail messages: $12 - 2 = 10$

Change in days: $\text{Wednesday} - \text{Sunday} = 3 \text{ days}$

So, the rate of change is: $\frac{10}{3} \approx 3.3 \text{ messages per day}$

Thus, the rate of change is 3.3 voicemail messages per day (rounded to the nearest tenth).

Would you like more details or have any other questions?

Here are five related questions to expand this concept:

1. What would be the rate of change between Monday and Thursday?
2. How would the rate of change differ if the messages increased instead of decreased?
3. What does a negative rate of change indicate in this scenario?
4. How would you calculate the total number of messages deleted from Sunday to Thursday?
5. How does this concept of rate of change apply to other real-world examples like speed or temperature?

Tip: Always subtract in the order specified in the question (final value minus initial value) to avoid sign errors.