Plotting Points on Normal Probability Paper: Tips & Tricks

[axnman]

Jus some confusion over plotting points on normal probability paper..

1. Order the data
2. Do we do (i-0.5)/n where i=no. of observation and n= no. of samples?
believe can't use Z(i)= (X(i)- Mean)/ stand. dev. as i need to find both mean and std. dev from the graph...
What is the graph plotted for...i mean i have X(i) Vs Z(i) but seem a bit in circles.

can anybody please let me know?thanks

 

[HallsofIvy]

Jus some confusion over plotting points on normal probability paper..

1. Order the data

Okay, that should be easy.

2. Do we do (i-0.5)/n where i=no. of observation and n= no. of samples?

Do that for WHAT? I have no idea what you are taking about here.

believe can't use Z(i)= (X(i)- Mean)/ stand. dev. as i need to find both mean and std. dev from the graph...[\quote]
Use it for WHAT?

What is the graph plotted for...i mean i have X(i) Vs Z(i) but seem a bit in circles.

can anybody please let me know?thanks

What graph are you talking about? You don't actually state what your problem is!

 

[Architeuthis Dux]

I can offer some tips and tricks for plotting points on normal probability paper. First, it is important to order your data from smallest to largest. This will help with visualizing the distribution of your data on the graph.

Next, the formula (i-0.5)/n is used to calculate the probability of a data point falling within a certain range. This formula is used for calculating the z-score, which represents the number of standard deviations a data point is from the mean. This is helpful for understanding the spread of your data and identifying any outliers.

The graph itself is plotted with X(i) on the horizontal axis and Z(i) on the vertical axis. This allows for a visual representation of the data in terms of standard deviations from the mean.

In terms of finding the mean and standard deviation from the graph, you can estimate them by looking at the shape of the data on the graph. The mean will be at the center of the curve and the standard deviation can be estimated by looking at the spread of the data points. However, for more accurate calculations, it is recommended to use statistical software or formulas.

I hope this clears up any confusion and helps with your plotting on normal probability paper. Remember to always order your data and use the appropriate formulas for calculating probabilities and identifying the mean and standard deviation. Good luck with your analysis!