A regression with two or more predictor variables is called a multiple. regression. (When we need to note the difference, a regression on a single predic-. tor is called a simple regression.) Weâd never try to find a regression by hand, and. even calculators arenât really up to the task.
Different jurisdictions have different definitions of what constitutes a prescription drug. Rx is often used as a short form for prescription drug in North America-a contraction of the Latin word  recipe  (an imperative form of recipere) meaning take.
Receive your authenticated prescription Costas. Once completed, your Costa Rx lens will have the Costa lens etching and will come with an authenticity card. This card guarantees your prescription Costa are the same great quality as non-prescription Costas.