Hypothesis testing

Doctors nationally believe that 70% of a certain type of operation are successful. In a particular hospital, 42 of these operations were observed and 32 of them were successful. At a - 0.05 is this hospital's success rate different from the national average? Yes, because the test value 0.52 is in the critical region. No, because the test value 0.52 is in the noncritical region. No, because the test value 0.88 is in the noncritical region. Yes, because the test value 0.88 is in the noncritical region. A doctor claims that the standard deviation of systolic blood pressure is 12 mmlig. A random sample of 24 patients found a standard deviation of 14 mmlig. Assume the variable is normally distributed. At a = 0.01, what are the critical x2 values? 13.848 and 36.415 13.091 and 35.172 9.262 and 44.181 11.524 and 44.314