If the data are moderately non-symmetrical, then which one of the following empirical relationships is correct?

• A

  $2 \times$ Standard deviation $=5 \times$ Mean deviation
• B

  $5 \times$ Standard deviation $=2 \times$ Mean deviation
• Correct answer
  C

  $4 \times$ Standard deviation $=5 \times$ Mean deviation
• D

  $5 \times$ Standard deviation $=4 \times$ Mean deviation

Hence, the correct answer is option: 'C'.