I agree with bob.
excel can truncate values in a display, but use the actual number for a
calculation.
For example:

we all know 4*3=12
but 4.4*3.4=14.96
If excel is not displaying the decimal points this would look like
4*3=15

for your numbers,
4251.290235*366.6=1558523
but excel might display
4251*367=1558523

"DC" wrote:

Thanks for the reply. The output I am receiving is "1,558,523" while the
correct answer is "1,560,117" to the formula "4251*367". Am I missing
something?

"Bob I" wrote:

You are likely not looking at or considering the "whole" content of the
2 cells being multiplied. Look at the complete values, not the rounded
or truncated displayed values.

DC wrote:
I have a simple formula multiplying two cells and the ouput is incorrect. Why
is this happening?