The phrase "a rate which" is correct and usable in written English.
It can be used when referring to a specific rate in a descriptive or explanatory context.
Example: "The company offers a rate which is competitive compared to other providers in the market."
Alternatives: "a rate that" or "a rate of".
Over the past year, he says the project has made strides, selling about 400 housing units a month – a rate which Ho describes as "healthy".
The Omori law states that the aftershocks which follow an earthquake occur at a rate which decreases predictably with time.
Australia went along at almost five an over, a rate which the loss of four wickets did nothing to negate.
These children's brains will develop physically at a rate which is quite different from those who are growing up in a normal, balanced environment".
By Thessaly La Force April 5, 2010 Yesterday, we learned that Apple sold more than 300,000 iPads on its first day (at a rate which would give one to every man, woman, and child in Mexico by next year).
Yesterday, we learned that Apple sold more than 300,000 iPads on its first day (at a rate which would give one to every man, woman, and child in Mexico by next year).
A relative novice – he came first in his very first international race at the Paralympic World Cup in Manchester in May – he has been improving at a rate which makes him a serious contender for the final.
If my fellow critic still hasn't got the gist of it, he will do soon: shared cinematic universes are now popping into existence at a rate which Stephen Hawking would struggle to keep up with.
Despite the regular visits to Detroit by ships to take away the petcoke, the oil sands bitumen refinery there is producing the material at a rate which means the waterfront pile continues to grow.
The combined efforts of communities, government and NGOs means poverty is declining in Liberia but not yet at a rate which will see the country meet its MDGs targets by 2015.
Some lenders, such as Lloyds and Nationwide only charge a non-refundable booking fee of £99 to reserve a rate, which is less of a hit, while others don't charge any non-refundable fee upfront".
