The table shows the number of phones sold by a small cell phone provider in various years. Use a calculator to write a quartic model for the number of phones sold in a given year since 1996 and use the model to estimate the number of phones sold in 2005. Answers:
P(x) ≈ −0.44x4 + 10.10x3 − 75.75x2 + 232.11x − 103.94
The estimated number of phones sold in 2005 is 325.

P(x) ≈ −0.25x3 + 8.48x2 − 42.28x + 191.29
The estimated number of phones sold in 2005 is 339.

P(x) ≈ −0.44x4 + 10.10x3 − 75.75x2 + 232.11x − 103.94
The estimated number of phones sold in 2005 is 316.

P(x) ≈ 0.25x3 − 8.48x2 + 42.28x − 191.29
The estimated number of phones sold in 2005 is 316.