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 2000 and use the model to estimate the number of phones sold in 2014. Answers:
P(x) ≈ 0.37x4 + 9.46x3 − 88.64x2 + 280.06x + 600.03
The estimated number of phones sold in 2014 is 1,348.

P(x) ≈ 0.37x4 − 13.92x3 + 193.84x2 − 1107.44x + 2523.48
The estimated number of phones sold in 2014 is 1,029.

P(x) ≈ −0.50x3 + 13.98x2 − 32.62x + 335.79
The estimated number of phones sold in 2014 is 1,084.

P(x) ≈ 0.50x3 − 13.98x2 + 32.62x + 335.79
The estimated number of phones sold in 2014 is 1,001.