title: How to find missing values?
body: <p>What are the techniques (such as KNN, Max likelihood) that I can use to find the missing values? 
  I want to use R and trying to find a suitable technique to impute the missing values.</p>
  
  <p>The sample data is shown below:</p>
  
  <pre><code>F1  F2  F3  F4  F5  Class
  Good    20  5   7   Old Normal
  Good    Missing 8   8   Old Normal
  Good    15  10  10  Old Normal
  Good    50  10  10  Old Normal
  Good    70  10  10  Old Abnormal
  Bad 20  5   7   Old Abnormal
  Good    20  5   80  Old Abnormal
  Good    85  100 100 Old Abnormal
  Good    20  100 Missing Old Abnormal
  Good    24  6   8.4 Old Normal
  Good    12  9.6 9.6 Old Normal
  Good    18  12  12  Old Normal
  Good    60  12  12  Old Normal
  Good    84  Missing 12  Old Abnormal
  Bad 24  6   8.4 Old Abnormal
  Good    24  6   96  Old Abnormal
  Good    102 120 120 Old Abnormal
  Good    24  120 72  Old Abnormal
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/kbqQR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kbqQR.png" alt="enter image description here"></a></p>