The accompanying file contains data for y. 

a. Estimate an autoregressive model of order 1, y_t = β₀ + β₁y_t−1 + ε_t, to make a one-step-ahead forecast (t = 25) for y. 

b. Estimate an autoregressive model of order 2, y_t = β₀ + β₁y_t−1 + β₂y_t−2 + ε_t, to make a one-step-ahead forecast (t = 25) for y.

t	y
1	29.32
2	30.96
3	35.79
4	38.79
5	42.73
6	42.49
7	43.06
8	45.16
9	46.31
10	45.66
11	48.46
12	45.52
13	48.83
14	47.84
15	46.01
16	44.93
17	47.77
18	45.63
19	45.38
20	45.78
21	44.84
22	46.86
23	48.12
24	48.58