To find this weighted average you have to find the total combined price and then divide it by the total purchases.
The first 1200 L cost 95.1 cents/L. We multiply the amount by the cost and we get: `1200 xx 96.1= 115,320` cents for the purchase
Next we multiply the second amount 1,525 L by its unit price 95.1 cents/L to get a total price of `1525 xx 95.1=145,027.5` cents.
Then we multiply the third amount 1700 L, by its unit price of 89.1 cents/Litre and get `1700 xx 89.1=151,470` cents.
To find the average price per Litre, we add up the price of all the purchases, and divide the sum by the total litres of fuel bought.
`(115,320+145,027.5+151,470)-:(1200+1525+1700)=` `411,817.5-:4425=93.1` Cents/L