The May 1, 2009 issue of The Montclarian reported the fol-
lowing home sale amounts for a sample of homes in Alameda,
CA that were sold the previous month (1000s of $):

590 815 575 608 350 1285 408 540 555 679

a. Calculate and interpret the sample mean and median.
b. Suppose the 6th observation had been 985 rather than
1285. How would the mean and median change?
c. Calculate a 20% trimmed mean by first trimming the two
smallest and two largest observations.
d. Calculate a 15% trimmed mean.

Question

The May 1, 2009 issue of The Montclarian reported the fol- 
lowing home sale amounts for a sample of homes in Alameda, 
CA that were sold the previous month (1000s of $): 

590 815 575 608 350 1285 408 540 555 679 

a. Calculate and interpret the sample mean and median.
b. Suppose the 6th observation had been 985 rather than
1285. How would the mean and median change?
c. Calculate a 20% trimmed mean by first trimming the two
smallest and two largest observations.
d. Calculate a 15% trimmed mean.

kropot72 · Answer

a. To calculate the sample mean, add the 10 amounts and divide the total by 10.
To find the median, rank the amounts in ascending order (lowest amount first). Since there is an even number of data the median is found by taking the arithmetic mean of the fifth and sixth amounts.

eujc21 · Answer

Thanks.