Question: how to calculate correlation p value?
Answer: You will use technology to calculate the p-value. ... 
The p-value is calculated using a t-distribution with n – 2 degrees of freedom.
The formula for the test statistic is t=r√n−2√1−r2 t = r n − 2 1 − r 2 . ... 
The p-value is the combined area in both tails.