a wording problem problem

ashycal

when practice question say: a study was conducted to determine whether the standard deviation of monthly costs of PA company is $300, why the correct null hypothesis H0= standard deviation of the population=300, it really sounds like Ha=300???

invic

Also, in chi-square problem, when the H0>16, Ha<16, DF=23, significant level=0.05, why i should look at the 0.95 column(yes, 95% probability in the right tail), and reject the null if chi-square is less than the critical value? why less than?