To find out how many senior lunches the grant can provide, you divide the total grant amount by the cost per lunch.
The grant amount is \(1.925 \times 10^6\) dollars, and the cost per lunch is $2.75.
Now, perform the division:
\[ \frac{1.925 \times 10^6}{2.75} \]
First, divide \(1.925\) by \(2.75\):
\[ 1.925 \div 2.75 \approx 0.7 \]
Now, we multiply that result by \(10^6\):
\[ 0.7 \times 10^6 \]
To express this in proper scientific notation, we can convert \(0.7\) to \(7\) by shifting the decimal point one place to the right, which means we need to decrease the exponent of \(10\) by 1:
\[ 0.7 \times 10^6 = 7 \times 10^5 \]
Thus, the number of senior lunches the grant can provide, expressed in scientific notation, is:
\[ 7 \times 10^5 \]
So the correct answer is 7×10^5.