Question

On a graph with y axis is 0 to 20 and x axis is 0 to 20, with points at 4,6 and 9, 6 and 10, 15 and 12 , 18. What is the average number of heartbeats per second
A. 2/3
B 1 1/2
C 2
D 3

Answer 1

To find the average number of heartbeats per second from the given points, we first need to clarify what the points represent.

If we interpret the coordinates as follows:
- (4, 6)
- (9, 6)
- (10, 15)
- (18, 12)

Let's assume that the x-axis represents time in seconds and the y-axis represents heartbeats.

1. **Identify the total number of heartbeats and the total time:**

- From (4, 6): 6 heartbeats at 4 seconds.
- From (9, 6): 6 heartbeats at 9 seconds.
- From (10, 15): 15 heartbeats at 10 seconds.
- From (18, 12): 12 heartbeats at 18 seconds.

**Total heartbeats:**
- At 4 seconds: 6 beats
- At 9 seconds: 6 beats
- At 10 seconds: 15 beats
- At 18 seconds: 12 beats

**Total heartbeats = 6 + 6 + 15 + 12 = 39 heartbeats.**

**Total time:**
The time interval would be from the first point to the last point, which is from 4 seconds to 18 seconds.

**Total time = 18 - 4 = 14 seconds.**

2. **Calculate average heartbeats per second:**

Average heartbeats per second = Total heartbeats / Total time

Average heartbeats per second = 39 heartbeats / 14 seconds = 2.7857 (approximately).

This value rounds to approximately 3 heartbeats per second.

Therefore, the answer is **D. 3**.