Statistics Help @ Talk Stats Forum
http://www.talkstats.com/
Free statistics help forum. Discuss statistical research, data analysis, statistics homework questions, R, SAS, Stata, SPSS, and more.enTue, 30 Sep 2014 23:45:52 GMTvBulletin60http://www.talkstats.com/images/misc/rss.pngStatistics Help @ Talk Stats Forum
http://www.talkstats.com/
Process Control
http://www.talkstats.com/showthread.php/57864-Process-Control?goto=newpost
Tue, 30 Sep 2014 14:28:30 GMTHi,
Could anyone help me with a statistical process control problem i have?
I am measuring a process which gives a measured value range from 0...Hi,

Could anyone help me with a statistical process control problem i have?

I am measuring a process which gives a measured value range from 0 to infinite, although in practice values are mostly 0 with a few outliers typically reaching a max value of 10.

The measured values are never below 0 so i have a heavily skewed distribution with 0 being the most common value, typically the standard deviation will be about 0.4 with a mean of 0.2. I'll have 40-80 samples per month.

For my process to remain in control i need to show that 90% of my measurements have a value of less than 1 with a 95% confidence. What is the best way of doing this? I'd like to understand how to work this out.

Any help would be most appreciated.

thanks

Steve
]]>ProbabilityPresterJohnhttp://www.talkstats.com/showthread.php/57864-Process-ControlTime series forecasting
http://www.talkstats.com/showthread.php/57863-Time-series-forecasting?goto=newpost
Tue, 30 Sep 2014 14:22:36 GMTCan any one explain how to forecast volatility in stock markets using auto-regressive models like TARCH, EGARCH etc.Can any one explain how to forecast volatility in stock markets using auto-regressive models like TARCH, EGARCH etc.
]]>Regression Analysistimeserieshttp://www.talkstats.com/showthread.php/57863-Time-series-forecastingDecriptives return 0 when both N and sum = 1
http://www.talkstats.com/showthread.php/57862-Decriptives-return-0-when-both-N-and-sum-1?goto=newpost
Tue, 30 Sep 2014 13:02:32 GMTHi there,
I have a question regarding the decriptives command. I have created this easy example to show my question. In the table below, there are...Hi there,

I have a question regarding the decriptives command. I have created this easy example to show my question. In the table below, there are four persons (A-D) who each have 6 tries.

Try A B C D
1 1,00 ---- 1,00 2,00
2 ---- 1,00 ---- ----
3 ---- 1,00 ---- ----
4 ---- ---- ---- ----
5 ---- ---- 1,00 ----
6 ---- ---- 1,00 ----

When I use the descriptives command, it returns the following output:

Descriptive Statistics
- N Sum
A 1 ,00
B 2 2,00
C 3 3,00
D 1 2,00
Valid N (listwise) 0

Can anyone explain to me why A gets ,00 instead of 1,00?