Do not average two quit-tracking averages without their observation counts

Check that the groups can be combined

Confirm the unit, recording definition, and known observations in each group. The groups must not overlap for simple addition of their totals. Two summaries of the same days cannot be combined this way. Also distinguish recorded observations from a calendar period that includes days with no usable entry.

NIST defines a mean from the sum of observations and their count. The recombination exercise here follows that arithmetic definition; it is not a quitting recommendation or a No Vape calculation feature. More decimal places cannot repair unlike units, incomplete coverage, or a group mean whose denominator you do not know.

National Institute of Standards and Technology: NIST/SEMATECH e-Handbook: Measures of Location

Calculate a fictional example from totals

Suppose one complete invented group contains two daily observations totaling 4, giving a mean of 2. A second disjoint group contains six compatible daily observations totaling 36, giving a mean of 6. Across all eight observations, the total is 40 and the mean is 5.

Averaging the two group means equally gives 4, which treats the two-observation group as having the same influence as the six-observation group. That is an average of group summaries, not the mean of all eight original observations. The numbers are fictional recorded counts, not actual use data, targets, or evidence of improvement.

Use known counts without inventing missing totals

Where a group mean is exact and its count is known, their product recovers its total arithmetically. A rounded mean may not recover the original total exactly. Prefer retained original totals when they are available, and keep any precision limit visible rather than treating a displayed average as complete raw data.

If you have only “one week averaged 2; another averaged 6,” you still need the definition and counts. Do not assume seven complete observations in each because the labels say week. Missing entries remain unknown. A combined number should not hide a period with different observation coverage.

Keep the calculation tied to a useful question

An overall mean can summarize all known compatible observations, but it cannot show which day or context needs attention. Retain separate groups when the difference itself matters. You can calculate an accurate combined mean and still prefer a dated context note for deciding how to arrange your next break.

State the output narrowly: “This mean summarizes these eight known observations under one rule.” It does not describe every unrecorded day or an individual health change. If the inputs are not suitable, the honest result is that no combined mean is established. There is no need to force your history into one number before continuing your current plan.