Rounding in Aplia Statistics Problems
Rounding can often be a confusing topic. We wanted to provide you with some information about our
conventions so that you can focus on interacting with the content, not wondering how to round it!
The basic convention we follow in Aplia-authored problems is:
When the digit to the right of the rounding digit is 5 or greater, the rounding digit is increased by 1
Rounding for intermediate calculations (i.e., chains of operations that are performed to arrive at an
answer; student does not enter any answers into Aplia): No rounding
Rounding for intermediate results (i.e., steps of a calculation that lead to a final answer; student does
enter answers for the steps into Aplia): To 4 places (or number of places indicate in the problem).
Students will then use the rounded intermediate result(s) to compute the subsequent dependent parts
of the problem.
Final answer rounding: To 2 decimal places
Test statistics: To 2 decimal places
Critical values: To 3 decimal places
Probability: Usually to 4 places
If we deviate from this, as we might in some problems, we will give instructions in the problem to this
effect. Note that when we show intermediate calculations in an Explanation we round to four places for
efficiency.
When we write “distracters” (in other words, the wrong answer choices in a drop-down list), we try to
create them so that they reflect mistakes in method or understanding, not mistakes in rounding. So if
you come up with an answer that is quite close to but not exactly the same as one of the drop-down
choices, choose the answer closest to yours.
If a problem is labeled as end of chapter or end of section, the rounding conventions used will match
those of the textbook. Often these kinds of problems do not include instructions for intermediate
rounding—when we transform these into their digital versions we will try to add in hints about whether
and how to round for intermediate steps.
We have created some tutorial problems on rounding if you’d like to see how this works or do some
quick practicing. You’ll find them in the same location as the Introduction to Aplia set.
Thanks! The Aplia Statistics Team