Free practice · single-choice · easy
Practice
Choose a weighted-average setup
Which setup finds the average price across 10 units at USD 8 and 30 units at USD 12?
Combination math map
Use equal weights only when the observations are equally weighted
Simple mean
NumeratorSum of values
DenominatorEqual count
Weighted mean
NumeratorΣ value × weight
DenominatorΣ weights
Allocation
ShareWhole × part/total
CheckParts + remainder
Weighted means preserve quantities, proportional allocations preserve shares, and a remainder check reconnects every part to the original whole.