Part-1
- First, reset the lower limit to zero and the upper limit to 1000, and then click update.
- Now put 6 points between 0 and 200 on the line. (You do that by clicking on the line at the place where you want to add the point.)
Assume that these data points represent the selling prices of houses in thousands of dollars in a particular neighborhood.
- Record the mean and the median for those six data points.
- Next, add one more point close to 1000.
That would represent the selling price of a house that sold for close to 1,000,000 dollars.
- Record the new mean and median for the seven points that you now have.
1. List the mean and median for the first six data points you entered.
2. List the mean and median after you added the seventh data point.
3. What impact does the outlier (the house with selling price close to 1,000,000 dollars) have on the mean and on the median?
4. Suppose the data points represent the selling prices of houses. After adding the seventh data point, would the mean or the median be the better measure of central tendency to use to report the "typical" selling price of a house in this neighborhood? Explain your answer.
Part-2
- First, reset the lower limit to zero and the upper limit to 20.
We will create three data sets with eight data points in each set.
- Create the first data set by inserting eight data points approximately evenly spaced between 0 and 20 along the line.
- Record the standard deviation of this data set.
- Now delete the first data set by clicking on the trashcan.
- Create the second data set by inserting eight data points all very close to 10 on the number line.
- Record the standard deviation of this data set, and then delete that data set.
- Last, create the third data set by inserting 4 points very close to zero and another 4 data points very close to 20.
- Record the standard deviation of this data set.
1. Which data set has the lowest standard deviation?
2. Which has the highest?
3. Is this what you expected? Why or why not?