Before Jonas Salk discovered a vaccine to prevent polio, people noticed a correlation between outside temperature and the incidence of polio: The warmer the temperature over the course of the year, the more outbreaks of polio. This relationship is an example of a(n) ________ correlation.
a. negative
b. positive
c. spurious
d. illusory

This term is used to describe the measure of how strongly two or more variables are close of related to each other. It has a null , one-tailed and Alternative Hypothesis.

Positive Correlation:

This simply implies that means that an high values of one variable are linked with high values of the another or based on your preference, the variables increase together.

The Strengths of correlation is a method to showing possible relationships between variables and othertime are the only practical or ethical way of carrying out an investigation..

The Weaknesses of correlation is that correlationall analysis do not show or demonstrate a cause and effect relationship that exists between variables understudy.