To find the total number of heartbeats occurring in Massachusetts per year, you multiply the average number of heartbeats per person by the population of Massachusetts.
Given:
- Average heartbeats per year per person = \(3.5 \times 10^7\)
- Population of Massachusetts = \(7 \times 10^6\)
Now, perform the multiplication:
\[ \text{Total heartbeats} = (3.5 \times 10^7) \times (7 \times 10^6) \]
When multiplying in scientific notation, you multiply the coefficients and add the exponents:
\[ = (3.5 \times 7) \times (10^7 \times 10^6) = 24.5 \times 10^{13} \]
Now, we want to express \(24.5\) in proper scientific notation:
\[ 24.5 = 2.45 \times 10^1 \]
Now substitute this back into the expression:
\[ 24.5 \times 10^{13} = 2.45 \times 10^1 \times 10^{13} = 2.45 \times 10^{14} \]
Thus, the total number of heartbeats occurring in Massachusetts per year is:
\[ \boxed{2.45 \times 10^{14}} \]