Autocorrelation

G’day all

Does anyone know why in reading 11 question 13a the answer stipulates “the test statistic for each lag is significant at the 0.01 level”? There was no significance level mentioned previously in the question, additionally wouldn’t it be that there would be no significance at any significance level given the test stats aren so high? The answer does not seem all that clear, but its probably me all the way… Cheers in advance to anyone with feedback to offer…

Yup…so strange, especially because the Blue Box usually use 5%

however the underlying concept here is same like in the Blue Box 6.