In a cardiac output of 5250 mL per minute, with 75 heartbeats per minute, the stroke volume is

Options

A. (a) 60 mL
B. (b) 80 mL
C. (c) 55 mL
D. (d) 70 mL

Explanation

To find the stroke volume given the cardiac output and heart rate, we can use the following formula:

**Step 1: Understand the formula for cardiac output.**
The formula for cardiac output (CO) is:
\[ \text{CO} = \text{Stroke Volume (SV)} \times \text{Heart Rate (HR)} \]

**Step 2: Identify the values given in the question.**
- Cardiac Output (CO) = 5250 mL/min
- Heart Rate (HR) = 75 beats/min

**Step 3: Rearrange the formula to solve for stroke volume.**
To find the stroke volume, we can rearrange the formula:
\[ \text{Stroke Volume (SV)} = \frac{\text{CO}}{\text{HR}} \]

**Step 4: Substitute the known values into the formula.**
Now, substitute the values we have:
\[ \text{SV} = \frac{5250 \text{ mL/min}}{75 \text{ beats/min}} \]

**Step 5: Perform the calculation.**
Now, calculate the stroke volume:
\[ \text{SV} = \frac{5250}{75} = 70 \text{ mL} \]

**Step 6: State the final answer.**
Thus, the stroke volume is 70 mL.

### Final Answer:
The stroke volume is **70 mL**.

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