How can I get java's random generator to produce a double for variable in a constructor statement?

Preface: I am new at this. Here is the source code file that won't compile because I get the error message that "method next double in class Random cannot be applied to given types."

import java.util.Random;
public class Student
{
        private String name;
        private String address;
        private String major;
        private double GPA;
        
        Random generator = new Random();
        
        public Student (String studName, String studAddr, String studMaj)
        {
                name = studName;
                address = studAddr;
                major = studMaj;
                GPA = generator.nextDouble(.5, 4.0);
        }
        
        public Student (String studName, String studAddr)
        {
                name = studName;
                address = studAddr;
                major = "undeclared";
                GPA = generator.nextDouble(.5, 4.0);
        }

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