Match the format string to the type of variable it works with in scanf.
%f
float
%g
float
%lf
double
%d
int
%u
unsigned int
%c
char
%s
a C string (e.g., char *)
%p
an address (e.g. any pointer type, like int *)
%ld
long
%lu
unsigned long
%lld
long long
%llu
unsigned long long
Checkpoint2.8.2.Parsons Problem: File I/O.
Put the following lines of code in order to read a single integer value into the variable named population from the file demographics.txt. If the file cannot be opened, the code should print "Error opening file" and then quit with a call to exit().