Time: 20 minutes. This quiz is closed book.
The following questions ask you to draw Q-Q plots. In every case, let the X axis show the values of the "reference distribution" (or very large batch of data) and the Y axis show the values of a batch of data.
1. Sketch a Q-Q plot showing a batch that has longer tails (high and low) than the reference distribution.
2. Sketch a Q-Q plot where half of the batch consists of nondetects, all with the same detection limit. Assume all the detected values are above the detection limit.
3. Sketch a Q-Q plot where the reference distribution has a single mode and the batch has two widely separated modes.
4. Sketch a Q-Q plot, as accurately as possible (show scales on the axes), where the batch has a shape essentially identical to the reference distribution but has twice the spread.
5. Sketch a Q-Q plot, as accurately as possible (show values on the axes), where the batch differs from the reference distribution only in location.
6. Sketch a Q-Q plot where the batch is essentially identical to the reference distribution but has two high outlying values.
7. Sketch a plot that consists of a curve in the X-Y plane but that cannot be a Q-Q plot for any possible set of data.
8. Ln(2) = 0.7 and Ln(5) = 1.6
(approximately). Compute (to one decimal place), showing your work:
a) ln(10)
b) ln(40)
c) log2(5)
d) ln(0.5)
e) exp(ln(2))
Scoring: The passing score is 96.
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This page was created 26 January 2001.