Econ 31 Fall 1999
Assignment 1: Descriptive Statistics (mean, median, mode,
frequency distribution)
Reading assignment: Mirer Chapters 1-4.
1. Four Eddie Bauer shirts cost $25, $32, $19, and $23.
a. Calculate the mean and standard deviation.
b. If you had just returned from a year at LSE, and had no shirts
and no
American dollars,but a wallet of poundage, what would the mean and
standard
deviation be on the shirt prices, in pounds given that your fixed
exhange rate is
$1.66 = 1 pound stirling and you are charged a 1 pound surcharge for
every
purchase (for foreign currency)?
c. If you subtract 10 dollars from each of the original prices
(your best
friend works at Eddie Bauer) and recalculated the mean, would the
standard
deviation change? Explain.
2 Create a set of ten family incomes which are simultaneously
consistent with
all three of the following statements:
i. On the average, the family income in my neighborhood equals
$35,000 per
year.
ii. On the average, the family income in my neighborhood equals $10,000 per year.
iii. On the average, the family income in my neighborhood equals
$2,000
per year.
3. a. Define these terms: mean, mode, median, and variance
b. When a frequency distribution exhibits positive skewness...
i. The mean exceeds the median.
ii. The mode exceeds the median.
iii. The median exceeds the mean and the mode.
Which is correct? Graph the frequency distribution.
c. Do you think that the median amount paid by Americans in income
tax in
1998 was less than the mean amount? Explain why this might occur and
draw
the frequency distribution for this situation.
4. Overheard in a Scottish pub: ''When a Scotsman moves from
Scotland to
England, he improves the IQ in both places.'' How could this be
possible?
Impossible? What would you hear in an English pub?