请问这里为什么不考虑t test的结果

问题如下：

Question

An analyst forecasts the quarterly earnings growth of an airline using ten years of data and an AR(1) process with a fourth-quarter seasonal lag specified as:

EarnGrowth_t = b₀ + b₁(EarnGrowth_t–1) + b₂(EarnGrowth_t–4) + ε_t.

The coefficient estimates and t-statistics are as follows:

If the earnings growth was 2% in the most recent quarter and 3% four quarters ago, the predicted earnings growth for the current quarter is closest to:

选项：

A.A.3.2%. B.B.4.4%. C.C.5.1%.

解释：

• A is Incorrect because the earnings growth calculation mixes up the estimated earnings growth coefficients: 0.025 + 0.850(0.02) − 0.320(0.03) = 0.0324 ≈ 3.2%.

• B is Correct because the earnings growth is calculated as: 0.025 − 0.320(0.02) + 0.850(0.03) = 0.0441 ≈ 4.4%.

• C is Incorrect because the earnings growth calculation ignores the earnings growth in the previous quarter (which is statistically insignificant as the absolute value of the t-statistic is less than the critical value of 2.02 at the 0.05 significance level): 0.025 + 0.850(0.03) = 0.0505 ≈ 5.1%.