95% confidence intervals

05072020, 01:30 AM
(This post was last modified: 05072020 06:13 PM by Trond.)
Post: #1




95% confidence intervals
I just came up with this, after flipping through tables and books to do each stage of the confidence intervals. What do you think?
HP 67 Program: 95% Confidence intervals, one variable: Assumes normal distribution. I have obtained the coefficients from classic statistics literature on tdistributions and normal distributions. Collect data (one variable) with ∑+. Run A for 95% confidence interval of a sample size n=5; B n=10; C n=15; D n=20; E n=30 or above (E is exact at 60 but a good estimate; for other samples you can also try the next lower and higher value for an idea) The program puts the +/ value around the mean in in the X register and in variable Reg.1, the lower limit of the interval in R2, the upper limit of the interval in R3, number of data n in RA, the mean in RB (and Y register), the standard deviation in RC, and Student t value in RD LBL A 2 . 7 7 6 STO D GSB 1 RTN LBL B 2 . 2 6 2 STO D GSB 1 RTN LBL C 2 . 1 4 5 STO D GSB 1 RTN LBL D 2 . 0 9 3 STO D GSB 1 RTN LBL E 2 STO D GSB 1 RTN LBL 1 P<>S RCL 9 P<>S STO A Mean X STO B Stdv STO C RCL A SQRT / RCL D x STO 1 RCL B + STO 3 RCL B RCL 1  STO 2 RCL B RCL 1 RTN Example: What is the mean weight of adult blue whales in the wild, with a 95% confidence interval, assuming normal distribution? Say that we have the following sample of weights in metric tons from old whaling records: 90, 176.5, 95, 60, 92, 80, 100, 120, 62, 98 Collect data with ∑+ Run B: the +/ value is in the x register and the mean in the Y register : 97.35 tons +/ 23.63, or check by RCL 2 and RCL 3 (73.72120.98 tons) 

05072020, 12:00 PM
Post: #2




RE: 95% confidence intervals
Very nice, congratulations. Pedro


05072020, 04:47 PM
Post: #3




RE: 95% confidence intervals  
05082020, 11:57 PM
(This post was last modified: 05112020 12:55 PM by SlideRule.)
Post: #4




RE: 95% confidence intervals
Are you familiar with the HP25 program Mean, Std. Deviation, 90/95% Confidence Intervals, Mean ± CI (APol18; pgs. 9599), in HP25 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES, in the General Software Library? Although the title reflects poorly on the depth & breadth of the subject matter, the contents (especially APol18) may prove useful in your endeavors.
BEST! SlideRule 

05092020, 01:37 AM
(This post was last modified: 05092020 01:39 AM by Trond.)
Post: #5




RE: 95% confidence intervals
(05082020 11:57 PM)SlideRule Wrote: Are you familiar with the HP25 program Mean, Std. Deviation, 90/95% Confidence Intervals, Mean ± CI (APol18; pgs. 9599), in HP25 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES, in the General Software Library? Although the title poorly reflects on the depth & breadth of the subject matter, the contents (especially APol18) may prove useful in your endeavors. Thanks for the info! EDIT: link does not seem to work. Do you have another link? 

05092020, 12:49 PM
(This post was last modified: 05092020 12:51 PM by SlideRule.)
Post: #6




RE: 95% confidence intervals
Yes! Same location, different 'entry'. The original post is updated w/ 'new' link  sorry for any confusion  seems that links from a wellused search engine are site / time / etc. / SPECIFIC. This link is from a cached site, thanks for the headsup.
BEST! SlideRule ps: try HP25 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES then use the Adobe PDF icon on the right to download. 

05092020, 06:32 PM
Post: #7




RE: 95% confidence intervals
Great finding SlideRule, very interesting. You are right, titles does not reflect the real content. Pedro


05102020, 12:19 PM
Post: #8




RE: 95% confidence intervals
A working link for the HP65 version of the text: HP65 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES
the original post (HP65) Air Pollution Measurement Studies: Stationary Sources is also 'updated'. BEST! SlideRule 

05102020, 12:32 PM
Post: #9




RE: 95% confidence intervals
Right, the infoemation about confidense interval is in pg68 of the book, or pg75 in PDF. I check that you are always attentive. Pedro


« Next Oldest  Next Newest »

User(s) browsing this thread: 1 Guest(s)