Page 6 - FINAL CFA SLIDES DECEMBER 2018 DAY 4
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Session Unit 3:
11. Sampling and Estimation
Example, p.254: Suppose a sample contains the past 30 monthly returns for McCreary, Inc. The
mean return is 2% and the sample SD is 20%. Calculate and interpret the SE of the sample mean.
Example: From above, suppose that instead of a sample size of 30, we take a sample of the past 200
monthly returns. Now, calculate the SESM for the 200-return sample.
Any Observation?
As sample size increased from 30 to 200, SE decreased from 3.6% to 1.4%. WHY?
