Do you want to take a chance on an unknown quantity?

And almost every person around him is an unknown quantity.

Just because he called you 'friend' doesn't make him any less an unknown quantity!

As an enemy, he was still very much an unknown quantity to them.

Carter is the only unknown quantity of the four, and that fact alone says all I need to know.

It's not like large data centers are an unknown quantity.

"If we'd opened before, he would have been an unknown quantity."

Many voters, however, were willing to take a chance on unknown quantities.

"After all, I'm not exactly an unknown quantity around here."

Process by which sample data are used to indicate the value of an unknown quantity in a population.