I'm trying to understand whether the number of words used to title a problem are related to the time used to solve that problem. In order to do this, I have derived two vectors from my data-set, one vector contains values from 1 to 7 representing the number of words used to described a problem, the other vector contains the average time values of all the problems defined with a given number of words.
words 1 2 3 4 5 6 7 avg.time to solve (hrs) 450.3 510.1 560.2 631.9 720.4 706.6 690.8
Can I calculate the correlation between the number of words and the average values using the Spearman's rho? Is it correct?
Any reference is welcome