Question

"Given the scenario below, what is the critical value? Americans typically take off 5 sick days each year, with a standard deviation of 2 days. A researcher would like to know whether psychiatrists take off less sick days than the average American. The researcher obtains a sample of 16 psychiatrists who, on average, take 3 days of sick leave a year. Test this researcher s hypothesis using an alpha level of .01. "

Answer 1

γουν Date Given: Level of significance (2) 0.01 Standard deviation col= Alternate hypothesis (Hi): el (Less sick days) 2 < 2 When Hi contains less than sign, then we get critical value sign is negative By using z table, a=0.ot | -0-01 = 0.99 -Zeritical = Using z table, search o.gg or closer value in the body of the table, where all 4 decimal values are present. Do you see o-ggol which is closest to o.gg Hence we get Z 0.00 10.03 • 2.3 o-ggol Zc = Hence we get 2.3 to.03 2.33 - 2.33 (use negative sign) ANS : - 2.33