NO.PZ202306130100003402
问题如下：
Based on Exhibit 1, Olabudo should calculate a prediction interval for the actual
US CPI closest to:
选项：
A.2.7506 to 2.7544.
2.7521 to 2.7529.
2.7981 to 2.8019.
解释：
A is correct. The forecast interval for inflation is calculated in three steps:
Step 1. Make the prediction given the US CPI forecast of 2.8:
Step 2. Compute the variance of the prediction error:
计算prediction interval的时候那个tc =2怎么算出来的
