Question 1157713
<pre>
     X       f        f∙X
  $21,000​   14      $294000
  ​$23,500​   12         ?
  ​$27,500​   18         ?
  $31,500​    3         ?
  $38,700    5​         ?  
 ​$146,700    1         ?
--------------------------
         n = ?   sum = ?

Put numbers where the question marks are.

Multiply each of the X-values by the f value
to finish the f∙x list.  (I did the first one,
you do the others)

Add the f column to get n

Add the f∙x column to get the sum.

Then divide the sum by n.

That will be the mean salary.

Edwin</pre>