Mutual fund prices precision

[Colin Law]

On 4 August 2015 at 08:18, Maf. King <maf at chilwell.net> wrote:
> On Tue 4 August 15 08:01:48 Colin Law wrote:
>> On 3 August 2015 at 22:31, AC <gnucash at acarver.net> wrote:
>> >> ..
>> >
>> > As an example, a purchase of 136.742 shares (same precision as the
>> > statement) for a total price of $650.89 (also same precision) and the
>> > price per share is 4.759 on the statement and 4.75999 in GC.  The
>> > statement lists prices per share to three decimals.  There is probably
>> > internal rounding on their system that I can not see because no
>> > statement or other record shows more than three decimals of price.
>>
>> Interestingly neither your bank nor GC seem to have correctly rounded
>> it, both have truncated.  If you get your calculator out and work out
>> 650.89/136.742 you will see the answer is 4.7599895959 (to that
>> precision).  So to three decimal places the correct rounded figure is
>> 4.760 and to five decimal places it is 4.76000.
>>
>
> Colin,
> surely the 5dp rounding should be 4.75999?

Oops, yes you are right, too many 8s and 9s for my old eyes and brain
to parse correctly.  So GC is correct to 5 places, but the statement
is wrong to 3 places.

Colin