Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
TI-83 Worksheet Number 27 Statistics – Normal Probability Plot Given the following set of data, check to see if it is close to a normal distribution. Speed 29 34 34 28 30 29 38 31 29 34 32 31 31 27 37 29 26 24 34 36 31 34 36 To check for normality, we make a probability plot. This is constructed by first finding the Z-scores for each of the numbers in the data list (recall the z-score = (data pointmean)/(standard deviation). We then plot the actual data on one axis and the corresponding z-scores on the other axis. If the result is a perfect straight line, then the data list is a linear transformation of the standard normal distribution and therefore the data list is normal. The data list is close to normal of the plot is close to a straight line. Key Strokes Stat Enter 29 Enter 34 Enter … 36 Enter 2nd Statplot Enter Enter ▼ ► ► ► ► ► Enter ▼ 2nd L1 ▼ ► Enter Zoom 9 www.mikeshoreline.com 5/6/2017 Comment Brings up List Editor. Select L1 Enter the data in L1 Selects and turns Plot1 Highlights the probability plot icon, the last icon in the second row. Enters L1 as the Data List Selects the y-axis as the Data Axis (It does not make any difference which axis is the data axis, but convention usually uses the y-axis as the data axis.) Display the plot. The solid vertical line is at the z-score =0 and will intersect the mean of the data. In this case the line is fairly close to a straight line, so the distribution of the data would be considered close to normal. WS 27 Page 1 of 1