Final answer:
The total number of text messages sent each year by all the people in Arizona is 59.2 billion.
Step-by-step explanation:
To calculate the total number of text messages sent by all the people in Arizona, we need to multiply the number of people by the average number of text messages sent per person. In this case, there were 7.4 million people in Arizona and each person sent an average of 8,000 text messages per year. So, the total number of text messages sent each year is:
Total number of text messages = Number of people x Average number of text messages sent per person
Total number of text messages = 7.4 million x 8,000
Total number of text messages = 59.2 billion