Q1) Median can be a more suitable measure of central tendency than mean if distribution of the data is extremely skewed.           

a) False   

b) True    

c) It does not matter, when data are skewed mean and median are the same

d) It does not matter, when data are skewed the mean, median, and mode are the same      

Q2) According to Chebyshev's theorem, proportion of values from data set which is further than two standard deviations from the mean is at most:

a) 0.50    

b) 0.13

c) 1.00

d) 0.25

Q3) In study of elephants researcher desires to find out average weight of certain subspecies of elephants.  From earlier studies, standard deviation of weights of elephants in this subspecies is known to be= 1500 pounds.  How many elephants does researcher require to weigh so that he can be 80% confident that average weight of elephants in his sample is within 350 pounds of true average weight for this subspecies?

a) 31       

b) 39       

c) 50       

d) 166