The following chloride (mmol/L) results were obtained using a new analyzer: 106 115 111 83 120 127 119 100 104 83 105 107 106 110 106 110 112 108 108 109 114 102. What is the mean?

• A. 108
• B. 105
• C. 109
• D. 107

Answer: (A)

Calculating the mean involves adding all the chloride results and dividing by how many measurements there are. Here there are 22 values, and their sum is 2365. Dividing 2365 by 22 gives 107.5 mmol/L. Since the choices are whole numbers, you round to the nearest integer, which is 108 mmol/L. So the best match is 108.