# Why is this normal probability plot graph skewed right?

First, I apologize for the bad image, but it's the best I can do with a mouse. Anyways, here it is:

So the data is skewed right, but the normal probability plot bends up and over what would be the approximate linear equation. According to different websites1, 2, a normal probability plot with data skewed right goes under the approximate line of best fit, and my graph looks more like it's skewed left. What am I misunderstanding?

1: itl.nist.gov/div898/handbook/eda/section3/normprp4.htm
2: www.basic.northwestern.edu/statguidefiles/probplots.html#Data%20Skewed%20to%20Right

• The graph is impossible to understand without labels and scales for the axes.
– whuber
Commented Oct 5, 2011 at 3:13
• It's a normal probability plot from -3 to 3 on the y-axis and time on the x axis. Commented Oct 5, 2011 at 3:14
• Assuming time increases left to right and y increases bottom to top and that the normal plotting positions have been correctly computed, this is a plot of right-skewed times. Why does it look skewed left to you?
– whuber
Commented Oct 5, 2011 at 3:18
• The websites show that right skewed graphs don't look like that, while it looks like the examples for left skewed graphs. Commented Oct 5, 2011 at 3:21
• Is that a frequency histogram at the top? If you best want to understand your question, try making the normal probability plot yourself, without a computer.