Marissa is reading over her blood work results from her doctor. According to the report, there are about 3.7 × 10^5 platelets and about 9,300 white blood cells in a microliter of blood. What is the total number of platelets and white blood cells in a microliter of blood?

To find the total number of platelets and white blood cells in a microliter of blood, you simply need to add the two quantities together.

The number of platelets is given as \(3.7 \times 10^5\) and the number of white blood cells is \(9,300\).

First, we can express \(9,300\) in scientific notation: \[ 9,300 = 9.3 \times 10^3 \]

Now, we can add the two values. However, to add these numbers directly, it's best to convert \(3.7 \times 10^5\) into the same power of ten as \(9.3 \times 10^3\).

Express \(9.3 \times 10^3\) in terms of \(10^5\): \[ 9.3 \times 10^3 = 0.093 \times 10^5 \]

Now both numbers have the same exponent: \[ 3.7 \times 10^5 + 0.093 \times 10^5 \]

Next, we can combine the coefficients: \[ (3.7 + 0.093) \times 10^5 = 3.793 \times 10^5 \]

Thus, the total number of platelets and white blood cells in a microliter of blood is: \[ \boxed{3.793 \times 10^5} \]