If A and B are disjoint, P(A) =0.4 and P(A or B)=0.9
If the variance for a data set is zero, then all the observations in this data set must be zero.
There may be more than one mode in a data set .
A 98% confidence interval is wider than a 95% confidence interval of the same parameter
In a two tailed test, the value of the test statistic is 2. The test statistic follow a distribution with the distribution curve shown is the area is 0.03, than we have sufficient evidence to reject the null hypothesis @ 0.05 level of significance.
Are these statement true or false and I would like to justify my answer.