22% of the Dutch population goes on a vacation in the Netherlands, 36% goes abroad for a vacation and 14% goes on a vacation in the Netherlands, and also goes abroad. The rest doesn't go on a vacation.
A research is conducted with 80 Dutch participants, calculate the chance that between 20% and 30% goes on vacation exclusively abroad (allowed to use a graphing calculator with binomcdf).
I thought you could just do:
$P (X \leq 24) - P (X \leq 16)$ = binomcdf (80 (# of trials), 0.36 (p), 24(# of succesfull trials) - binomcdf (80, 0.36, 16).
My textbook however says that it is:
$P (X \leq 23) - P(X \leq 16)$. Why is this?