Call non-const function on a const object

I am reading C++ Primer 5th edition page 258. The question is, can a const object call its non-const member function, even if that member function does not modify its data?

Sales_data.h

#include <iostream>
#include <string>

struct Sales_data {
    // data members
    std::string bookNo;
    unsigned units_sold = 0;
    double revenue = 0.0;

    // memeber functions
    const std::string isbn() const { return bookNo; }
    Sales_data& combine(const Sales_data&);
    double avg_price() const { // *
        if (units_sold) {
            return revenue / units_sold;
        }
        return 0.0;
    }
};

std::ostream& print(std::ostream &os, const Sales_data& data) {
    os << data.isbn() << " " << data.units_sold << " " << data.avg_price();
    return os;
}

use_Sales_data.cpp

#include <iostream>
#include "Sales_data.h"
using  namespace std;

int main(){
    Sales_data data;
    data.bookNo = "CSAPP";
    data.units_sold = 2;
    data.revenue = 50;
    print(cout, data);
}

When I remove the const for function avg_price, then the code does not compile. But I think the function avg_price() does not modify the object. My guessing is that, in the parameter list of print, I declared Sales_data object as const and C++ does not allow const object to call its nonconst member function. Is this the case?

Thanks for your time.