Kinda confused on this one, someone !

As x increases from 0 to 1, y decreases from 89 to 55.  This could happen if 89 were multiplied by the rate of change factor 0.62:  0.62(89) = 55.  Likewise, if we mult. 55 by 0.62, we get 34, which also agrees with the table values for y.

Thus, this is an example of exponential decay, with decay constant 0.62.

To determine which type of graph this is, look at the estimated population, and look at the differences between each point:

89, 55, 34, 21, 13

Differences: 34, 21, 13, 8

The differences are all different values, so linear can be removed.

Because the graph is decreasing at a rate, we can eliminate both quadratic answers, as they would have increasing values.

The answer is 'exponential; y = 89 * 0.62^x'.