A sample of 200 elements from a population with a known standard deviation is selected. For an interval estimation of , the proper distribution to use is the
a. normal distribution.
b. t distribution with 200 degrees of freedom.
c. t distribution with 201 degrees of freedom.
d. t distribution with 199 degrees of freedom.
Question 2
Which of the following forecasting methods puts the least weight on the most recent time series value?
a. exponential smoothing with = .3
b. exponential smoothing with = .2
c. moving average using the most recent 4 periods
d. moving average using the most recent 3 periods