Using awk for calculations, getting extra lines in the output

Question

I am trying to print a simple report with the awk command and with and some calculations. This is the input file:

1   Syed-Yamin   3   500
2   Ilia-Nika    4   400
3   Mike-Ro      5   300
4   Witold-Ryb   2   200
5   Farhan-F     1   500

In the report I want to print the 1st column, the 2nd column and the calculation result of multiplication of the 3rd and 4th columns for each row. Also, I want to print on the bottom the total of the all multiplications from each row. I am getting some extra lines in the output and would like to clean them up. So the end result should look like that:

1   Syed-Yamin   1500
2   Ilia-Nika    1600
3   Mike-Ro      1500
4   Witold-Ryb   400
5   Farhan-F     500
Total amount = $5500

awk 'BEGIN {total=0;}
{print "$1, $2, ($3 * $4)";}
total=total+($3 * $4)
END {print "Total Amount = $", total;}' input

awk print with lots of extra lines

Answer 1

here I fixed for you...

$ awk -v OFS='\t' '{$3 *= $4; NF--; total += $3}1
               END {print "","Total Amount =", "$"total}' file | 
 column -ts$'\t'

1  Syed-Yamin      1500
2  Ilia-Nika       1600
3  Mike-Ro         1500
4  Witold-Ryb      400
5  Farhan-F        500
   Total Amount =  $5500

perhaps better formatted this way

$ awk '{printf "%d\t%s\t%5d\n",$1,$2,$3*=$4; total+=$3}
   END {print "\tTotal Amount =\t$"total}' file | 
   column -ts$'\t'

1  Syed-Yamin       1500
2  Ilia-Nika        1600
3  Mike-Ro          1500
4  Witold-Ryb        400
5  Farhan-F          500
   Total Amount =  $5500