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  • Problem
  • Solutions

The table shows some information about family sizes.

Number of children 1 2 3 4 5
Number of families 6 13 9 4 1

Find:

a) the mean number of children in a family

b) the mean number of siblings that each child has
 

If you liked this problem, you might also like the longer problem it is based on, The Wrong Stats
You can find more short problems, arranged by curriculum topic, in our short problems collection.

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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