A study compared the number of users x (in millions) and the number of connections between users y (in millions) of a social network. The results are shown in the following table.

Use a graphing calculator to find
a model for the data and answer this question by giving values for a, b, and c,
where a, b, and c are constants in the equation y = ax^{2}+bx+c. Leave
all commas out of large numbers and round all three answers to the nearest
thousandth.

x |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
110 |

y |
42.4 |
47.5 |
53.2 |
54.1 |
54.9 |
56.7 |
57.2 |
56.9 |
57.3 |
56.1 |
54.3 |

a = _{}

b = _{}

c = _{}