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Anonymous A
on Mar 19, 2023
Global
Question about

Age group

If we assume equal distribution of age group, then there's 81 age group between 0-80. So for age 0 should be 330M/81? Why it's 330M/80? 

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Hagen
Coach
on Mar 21, 2023
#1 recommended coach | >95% success rate | 8+ years consulting, 8+ years coaching and 7+ years interviewing experience

Hi there,

I think this is an interesting question that may be relevant for many people. I would be happy to share my thoughts on it:

  • First of all, technically, between 0 and 80, there are only 80 age groups, not 81.
  • However, what is even more important, I would highly advise you not to overcomplicate things by being too precise in case studies. While calculating with 80 is a relatively easy task, doing so with 81 is significantly harder. Given that we are talking about a deviation of 1.25%, even if 81 were the correct number of age groups, you should take 80 and communicate the rounding.

If you would like a more detailed discussion on how to address your specific situation, please don't hesitate to contact me directly.

Best,

Hagen

on Mar 20, 2023
#1 Coach for Sessions (4.500+) | 1.500+ 5-Star Reviews | Proven Success: ➡ interviewoffers.com | Ex BCG | 10Y+ Coaching

Hi there,

Q: If we assume equal distribution of age group, then there's 81 age groups between 0-80. So for age 0 should be 330M/81?

Actually between 0 and 80 there are 80 age groups, as can assume the 80-81 is excluded:

  • 0-1 → #1
  • 1-2 → #2
  • 79-80 → #80

In any case, for market sizing it is fine to approximate (you should align with the interviewer on the approximation but normally there are no issues).

Best,

Francesco

Andreas
Coach
on Mar 20, 2023
McKinsey EM | Top MBB Coach | >70% Success Rate | Free Introductory Calls

Hi there,

assume 1/80 is the fraction of the population that sits in each age cohort. Make your assumptions transparent to the interviewer and you should be fine.

Best regards,

Andreas

Ian
Coach
on Mar 19, 2023
Top US BCG / MBB Coach - 5,000 sessions |Tech, Platinion, Big 4 | 9/9 personal interviews passed | 95% candidate success

Hi there,

You're overcomplicating.

I think you're missing the entire point of market sizing here….

Right now, you think you're supposed to get the exact right number. You're not!

You are just supposed to get a number within a reasonable range.

It doesn't matter if the true age range is 79 or 81.5 or 82.5

It doesn't matter if there is equal distribution or if it is slightly curved.

The point is you are estimating.

As such, you can divide by 80…

The point is that the added work in calculating 1/81 is not worth it EVEN IF it added more accuracy (which it won't, since we estimated 80 in the first palce!)

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