Q1) According to Chebyshev's theorem, proportion of values from data set that is further than 2 standard deviations from the mean is at most:

i) 0.50    

ii) 0.13

iv)1.00

v)  0.25

Q2) In study of elephants researcher wants to find out average weight of a certain subspecies of elephants.  From preceding 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?

i) 31       

ii) 39       

iii) 50       

iv)166     

Q3) A snack food manufacturer chosen sample of 15 bags of pretzels off assembly line and weighed their contents. If sample mean is 10.0 and sample standard deviation is 0.15, determine the 95% confidence interval estimate for true mean weight of bags of this kind of pretzel.

i) (9.92, 12.34)   

ii) (8.54, 11.46)

iii) (10.42, 10.58)

iv) (9.92, 10.08)