To find out how many senior lunches the grant can provide, you need to divide the total amount of the grant by the cost per lunch.
The grant amount is \( 1.925 \times 10^6 \) dollars, and the cost of each lunch is \( 2.75 \) dollars.
We can calculate the number of lunches as follows:
\[ \text{Number of lunches} = \frac{1.925 \times 10^6}{2.75} \]
First, perform the division:
\[ 1.925 \div 2.75 \approx 0.700 \]
Now, since we need to express this in scientific notation:
\[ 0.700 = 7.00 \times 10^{-1} , \text{(which is equivalent to 0.7)} \]
Now, multiplying by \( 10^6 \):
\[ 0.700 \times 10^6 = 7.00 \times 10^5 \]
Thus, in scientific notation, the number of lunches the grant can provide is:
\[ \boxed{7 \times 10^5} \]
So the correct answer from the options you provided is \( 7 \times 10^5 \).