Data interpretation

Standard deviation measures how much the values in a dataset deviate from the mean, representing the overall spread or variability of the data. In contrast, measures of central tendency, like the mean or median, describe the center or typical value of a dataset rather than its distribution.

Total annual sales can be found by summing the sales of each quarter.. Summing the quarterly sales 10 + 15 + 25 + 30 yields 80 thousand units, which is the total annual sales.

The correct answer is 80 because it is the sum of the sales of all four quarters. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !Some test-takers may misadd the sales figures or omit one of the quarters, leading to an incorrect total. A common mistake is adding 10 + 15 + 25 and then adding 25 again, instead of adding 30, resulting in 75 instead of 80.
• !Selecting $800 is incorrect because that represents the 40% allocated to rent rather than the portion spent on food.

Answer each from memory — you'll see instantly whether you're right and why.

Run a focused 10-question mini-mock on Data interpretation and see it stick.