If the value of test statistic does not lie between -1.96 and +1.96 then, the difference would be significant and the null hypothesis will be rejected.
Using the significance levels as reported by forecast Xtm, we would check the difference of means between the two items.
The critical value of Z at 95% confidence level is 1.96.
Then we would calculate the Test statistic, viz, difference of means/ standard deviation.
Decision Rule:
If we find that the value of test statistic is more than the value of Z, i.e., the test statistic does not lie between -1.96 to +1.96, then, the difference would be significant and the null hypothesis must be rejected.
But, the other way round, if the difference between the two means is not significant at the 95% confidence level, then the null hypothesis should not be rejected.
To know more about null hypothesis:
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