Write a Scheme function assignment-grade that consumes four integers (in the range 0 to 100), corresponding
to assignment marks, and produces the grade between 0 and 21, based on dropping the lowest assignment mark and
adding the bonus, if applicable. For example,
• (assignment-grade 100 100 100 100) = 21,
• (assignment-grade 61 62 61 0) = 184/15.
Note that your answer for the second example may appear in a different format, such as a decimal expansion.

Question

Write a Scheme function assignment-grade that consumes four integers (in the range 0 to 100), corresponding 
to assignment marks, and produces the grade between 0 and 21, based on dropping the lowest assignment mark and 
adding the bonus, if applicable. For example,  
• (assignment-grade 100 100 100 100) => 21,   
• (assignment-grade 61 62 61 0) => 184/15. 
Note that your answer for the second example may appear in a different format, such as a decimal expansion.