title: KO Computed variable will not update
body: <p>I have a bit of code I'm working on that is part of a larger budget application. This bit allows a use to input some reoccurring weekly expenses and the app will calculate monthly totals based on the input. Everything is working except the updating of the Monthly Amount in the table when editing an existing entry. The delete feature works updates the total monthly weekly expenses and adding a new entry does the same.</p>
  
  <p>The Weekly Amount in the table comes from the <code>self.weeklyExpense = new weeklyExpense();</code>. This object is created with the following external function.</p>
  
  <pre><code>function weeklyExpense(data) {
        if (!data) {
          this.name = ko.observable();
          this.weeklyAmount = ko.observable('0.00');
          this.monthlyAmount = ko.observable('0.00');
        } else {
          this.name = ko.observable(data.name);
          this.weeklyAmount = ko.observable(data.weeklyAmount);
          this.monthlyAmount = ko.computed(function() {
            console.log(data.weeklyAmount);
            var temp = data.weeklyAmount;
            return total = (Number(temp) * 4.4).toFixed(2);
          })
        }
      }
  </code></pre>
  
  <p>I have narrowed the problem down to the <code>this.monthlyAmount = ko.computed</code> variable, it isn't updating when the monthlyAmount changes. I have verified in the debugger that the <code>weeklyAmount</code> is changing but the computed variable is not updating. Any help would be greatly appreciated.</p>
  
  <p>Here is a link to a working <a href="https://jsfiddle.net/jokerfwb/4bp7Lp3b/" rel="nofollow noreferrer">JS Fiddle</a> example.</p>