1040.c

#include<stdio.h>

int main(){

    float N1, N2, N3, N4, avg1, s1, avg2;
    scanf("%f %f %f %f", &N1, &N2, &N3, &N4);

    avg1 = (N1*2 + N2*3 + N3*4 + N4*1)/(2+3+4+1);
    printf("Media: %.1f\n", avg1);

    if(avg1>7.0)
    {
        printf("Aluno aprovado.\n");
    }

    else if(avg1<5.0)
    {
        printf("Aluno reprovado.\n");
    }

    else if(avg1>=5.0 && avg1<=6.9)
    {
        printf("Aluno em exame.\n");
        scanf("%f", &s1);
        printf("Nota do exame: %.1f\n", s1);

        avg2 = (avg1 + s1)/2;

        if(avg2>5.0)
        {
            printf("Aluno aprovado.\n");
        }
        else if(avg2<4.9)
        {
            printf("Aluno reprovado.\n");
        }

        printf("Media final: %.1f\n", avg2);
    }

   return 0;
}