setprecision set larger than float sig digits

[Mihalko]

My instructor explained this to the class but no one could follow it and it is not in the textbook. Would someone please explain this in a manner that makes sense?

Why does fnum display as 42.987652? Where does the last 2 come from?
_____________________________
#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
double dnum = 42.98765;
float fnum = 42.98765;

cout << setprecision(6) << fixed;
cout << dnum << endl;
cout << fnum << endl;
cout << "Press 'enter' to exit..." << endl;
cin.get();
return 0;
}

[Bazzy]

Floating point notation leads to precision loss.
"double" actually means "double precision floating point" which means that it stores values in more bits than float.
Thus, you get a better precision using double, as the above example shows