81 articles tagged #Data Analysis
VLOOKUP always returns the first match it finds — so when your lookup table has duplicate keys, you get the wrong value with no error to warn you. Here's how to diagnose the problem and fix it for good.
AVERAGEIFS throws #DIV/0! and your named range looks perfectly fine — so what's going wrong? The culprit is usually a size mismatch or scope conflict that Excel silently fails on. Here's how to diagnose and fix it.
Your SUMIF looks right, your criteria is correct, but the total is off — and the only thing that changed was filtering or hiding some rows. Here's exactly why SUMIF ignores your hidden-row expectations and how to fix it.
Running pd.merge() and getting way more rows than expected? When join keys aren't unique on both sides, Pandas does a cartesian product on matches — and the result can silently balloon your DataFrame. Here's how to diagnose and fix it.
COUNTIFS with date ranges looks right but counts wrong — a frustrating bug that hides in plain sight. Learn exactly why Excel misreads your date criteria and the fixes that actually work.
Your INDEX MATCH formula looks perfect but keeps throwing #N/A — and the culprit is a merged cell in your lookup range. Here's exactly why this breaks and how to fix it without losing your layout.
Excel's AVERAGEIF throws a #DIV/0! error the moment its criteria match zero cells — even a single filter or typo can trigger it. Here's how to diagnose the root cause and wrap it safely.
Your SUMIF formula looks right but keeps returning zero. The culprit is almost always a silent offset mismatch between the criteria range and sum range. Here's how to diagnose and fix it fast.
When Excel's OFFSET function returns #REF!, it almost always means your row or column argument has pushed the reference outside the sheet. Here's how to diagnose the root cause and fix it permanently.
If SUMPRODUCT suddenly throws #VALUE! the moment you reference a second sheet, you're not alone. This guide explains exactly why multi-sheet ranges break SUMPRODUCT and gives you working alternatives that actually produce the right totals.
SUMPRODUCT is supposed to multiply and sum your arrays in one shot, but the moment a text value sneaks in, the total goes wrong with no error to warn you. Here's exactly why it happens and how to fix it.
AVERAGEIFS returning zero instead of an error or blank is one of those silent failures that corrupt your reports without warning. Here's exactly why it happens and how to fix it cleanly.