title: Shell script which finds the sum average and product of five numbers
body: <p>This is what I have so far:</p>
  
  <pre><code>echo "Please enter your first number: "
  read a
  echo "Second number: "
  read b
  </code></pre>
  
  <p>(etc..)
  That works fine, but when I tried to set a function for sum average and product, I ran into some problems.</p>
  
  <p>This is what I tried:</p>
  
  <pre><code>sum= ($a + $b + $c + $d + $e)
  avg= ($sum / 5) #The five was showing up in red text
  prod= ($a * $b * $c * $d * $e)
  
  echo "The sum of these numbers is: " $sum
  echo "The average of these numbers is: " $avg
  echo "The product of these numbers is: " $prod
  </code></pre>
  
  <p>but when I ran it (after I inputted the numbers 1,2,3,4,5) I got this back:</p>
  
  <pre><code>The sum of these numbers is: 1 + 2 + 3 + 4 + 5
  The average of these numbers is:  1 + 2 + 3 + 4 + 5 / 5
  The product of these numbers is: 1 * 2 * 3 * 4 * 5
  </code></pre>
  
  <p>So my question is how do I get these functions to compute within the () </p>
  
  <p>Any help is appreciated, thanks.</p>