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+--- Forum: HP Prime (/forum-5.html)
+--- Thread: Getting wrong result calculating EAR on HP Prime (/thread-860.html)
Getting wrong result calculating EAR on HP Prime - letrekk - 03-09-2014 02:50 AM
Hi all,
I'm new to the forum and I ended up here after searching on Google for 2 hours how to troubleshoot an issue with my Prime.
I'm trying to calculate an effective annual rate. I enter (1 + 0.1 / 12 ) ^ 12 - 1, and I get 0.1 (10%) as the result. This is inaccurate. The correct result is .1047130674 (approx 10.47%). I get this on both the Home and CAS modes.
Has anyone ran into the same issue? Is this an issue with my configuration or a known issue with the calculator?
I tried tweaking my settings for number format and simplification to no avail. I tried calling HP but they weren't able to help me. Any help will be very much appreciated.
RE: Getting wrong result calculating EAR on HP Prime - Helge Gabert - 03-09-2014 04:33 AM
Beats me . . . I get the correct result (number format standard).
RE: Getting wrong result calculating EAR on HP Prime - letrekk - 03-09-2014 04:54 AM
I think I've found the root of the problem and a workaround. If I am on the Finance App and then I go to Home or CAS and type the equation, the result is 0.1. If I change the mode (by opening any other app) and then go to Home/CAS I get the correct result (.1047130674).
It is easy to reproduce the problem. I'm not sure if this is by design or a behaviour bug. Either way, the workaround is simple.
RE: Getting wrong result calculating EAR on HP Prime - Tugdual - 03-09-2014 06:33 AM
This is because finance isn't math, by default all numbers are rounded to 2 decimal places. Also number format is set with [Shift + Symb] by default Fixed 2 which is consistent with your observations. Set this to System and [Shift+Home] (Settings) becomes the one place to go for setting format.
RE: Getting wrong result calculating EAR on HP Prime - letrekk - 03-09-2014 05:45 PM
(03-09-2014 06:33 AM)Tugdual Wrote: This is because finance isn't math, by default all numbers are rounded to 2 decimal places. Also number format is set with [Shift + Symb] by default Fixed 2 which is consistent with your observations. Set this to System and [Shift+Home] (Settings) becomes the one place to go for setting format.
Thank you so much for the clarification, Tugdual. I've now updated my settings.