Is this model adequate based on the sampling statistics? Be sure to comment on the model significance and interpret the Box-Pierce statistic results.

I believe the model is accurate. The P-value of the AR is less than the significance level of .05. We can conclude that the coefficient for the AR term is statistically significant. According to the Box-pierce results, the P-value at lag 12 is concerning as it is less than .05. The lag values at 24,36, and 48, are above .05 and conclude that the residuals are independent in the model. There should be enough to suggest the model is adequate. Am I interpreting this correctly?