Statistics and Data Analysis in Economics
Homework 2
Week of 1/25/99
- Reading Assignment:
Introductory Statistics for Business and Economics (ISBE)
- Chapter 2
- Suggested Problems (NOT to be handed in):
- 1) ISBE 2.6, 2.10-2.12, 2.19, 2.23, 2.29
- 2) The R&D expenditures (as a fraction of total
sales) for the 12 largest auto manufacturers, in a recent year, were
4.4, 3.6, 4.4, 3.7, 9.6, 3.9, 3.6, 3.5, 3.0, 4.5, 3.9, and 2.2.
- a) Calculate a five number summary of the data. What is
the IQR?
- b) Calculate the mean and standard deviation of the data.
- c) Remove the observation 9.6 (Daimler-Benz, an outlier)
from the dataset. Now recalculate the mean and standard deviation.
- d) With 9.6 removed from the dataset, refigure the 5 number
summary and IQR.
- e) Robust statistics are statistics less influenced by
exteme data points ("outliers"). Which measures of location and
dispersion are more robust, the moments (mean and standard deviation) or
percentile-based measures (median and IQR)?
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last updated 24 January 1999