Answer:
option b is the answer of your question
The third graph represents a function.
In a function, every input (x value) has <em>exactly</em> one output (y value). If even a single input has zero or two outputs, the graph does not represent a function.
A good way of testing this is using a vertical line. As you move a vertical line from left to right across a graph, it should always be touching exactly one point on the graphed line.
In this case, every graph fails this vertical line test except for the third graph, so the third graph represents a function.
The total would be $2.73.
3,989.237
A thousandth = 1/1000 = 0.001
Round 4th decimal place = 5
5 and over is rounding up and under 5 rounds down so it would be 3,989.237
2/3 hour is 40 minutes. 1 3/4 hour is 1 hour and 45 minutes. So she spent 1 hour and 5 minutes or 1 1/12 hour longer doing homework.
