Can someone please help me with this code? I don't know why it isn't working?

#include <iostream>
using namespace std;
/*
 * InflationRate - calculates the inflation rate given the old and new consumer price index
 * @param old_cpi: is the consumer price index that it was a year ago
 * @param new_cpi: is the consumer price index that it is currently 
 * @returns the computed inflation rate or 0 if inputs are invalid.
 */
void getCPIValues(float& old_cpi, float& new_cpi);
 
double InflationRate(float old_cpi, float new_cpi);

void swap_values(double& a, double& b);

void sort_array (double MAX_RATE[], int numRates);

double findMedian(double MAX_RATES[], int numRates);

const int MAX_RATES = 20;

int main()   //C++ programs start by executing the function main
{
   // #1: declare two float variables for the old consumer price index (cpi) and the new cpi
   float old_cpi, new_cpi, infrt, sum = 0, avg;
   char again;
   int crt = 0;
   double array[MAX_RATES];
   int numRates;

   do 
   {
       // #2: Read in two float values for the cpi and store them in the variables
        getCPIValues(old_cpi, new_cpi);
        
       // #3: call the function InflationRate with the two cpis
       // #4: print the results
        infrt = InflationRate(old_cpi, new_cpi);
        if (infrt != 0)
        {
          sum += infrt; crt++;
        }
        
        cout << "Inflation rate is " << infrt << endl;
        for (int i = 0; i < array[MAX_RATES]; i++)
            cin >> numRates;
            
        //int numRates = sizeof(array)/sizeof(MAX_RATES[]);
        
        
        // BONUS #1: Put the logic in #2-4 in a loop that asks the user to enter 'y' if there's more data
        cout << "Try again? (y or Y): ";
        cin >> again;
    } while((again == 'Y') || (again == 'y'));
    
    // BONUS #2: Keep a running total of the valid inflation rates and the number of computed rates to calculate the average rate.
    // Print the results after the loop
    // calculate average 
    avg = sum/crt;
    cout << "Average rate is " << avg << endl;
    
    cout << "Median rate is " << findMedian(MAX_RATES[], numRates) << endl;

   return 0;
}

// function ask the user to input the old and new consumer price indices
// check if the numbers are greater than 0 
void getCPIValues (float& old_cpi, float& new_cpi)
{
    do
    {
        cout << "Enter the old and new consumer price indices: ";
        cin  >> old_cpi >> new_cpi;
        if((old_cpi <= 0) || (new_cpi <= 0))
        {
            cout << "Error: CPI values must be greater than 0.";
        }
    } while ((old_cpi <= 0) || (new_cpi <= 0));
}

// double InflationRate(float old_cpi, float new_cpi)
// precondition:   both prices must be greater than 0.0
// postcondition:  the inflation rate is returned or 0 for invalid inputs
double InflationRate(float old_cpi, float new_cpi)
{
    if ((old_cpi <= 0) || (new_cpi <= 0) || old_cpi == new_cpi) 
    {
       return 0;
    }
    else
   // Implement InflationRate to calculate the percentage increase or decrease
   // Use (new_cpi - old_cpi) / old_cpi * 100
       return ((new_cpi - old_cpi) / old_cpi * 100);
}


void swap_values(double& a, double& b)
{
    double temp;
    a = b;
    b = temp;
    
}

void sort_array (double MAX_RATE[], int numRates)
{
    int index_of_smallest;
    
    for (int i = 0; i < numRates -1; i++)
    {
        index_of_smallest = i;
        for (int j = i+1; j < numRates; j++)
        {
            if (MAX_RATES[j] < MAX_RATES[index_of_smallest])
            {
                index_of_smallest = j;
            }
        }
        swap_values(&MAX_RATES[index_of_smallest], &MAX_RATES[i])
    }  
}

double findMedian(double MAX_RATES[], int numRates)
{
    // sort the array
   sort_array(MAX_RATES, MAX_RATES+numRates);
 
    // check for even case
    if (numRates % 2 != 0)
       return (double)MAX_RATES[numRates/2];
     
    return (double)(MAX_RATES[(numRates-1)/2] + MAX_RATES[numRates/2])/2.0;
}

 In function 'int main()':
61:55: error: expected primary-expression before ']' token
 In function 'void sort_array(double*, int)':
114:28: error: invalid types 'const int[int]' for array subscript
114:59: error: invalid types 'const int[int]' for array subscript
119:49: error: invalid types 'const int[int]' for array subscript
119:64: error: invalid types 'const int[int]' for array subscript
 In function 'double findMedian(double*, int)':
126:35: error: invalid conversion from 'double*' to 'int' [-fpermissive]
105:6: note: initializing argument 2 of 'void sort_array(double*, int)'