For each value of PC speed that exceeds 600 MHz, define the average price of the PCs with identical speeds.
Result set: speed, average price.
TRY executing the following syntax.
select speed, avg(price) as AVG_PRICE from pc where speed>600 group by speed
Right.
The result of Your query:
speedAVG_PRICE
750900.0000
800970.0000
900980.0000