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What are the formulae for the expectation of a sum and the variance of a sum?

In creating the trial simulation, you could use the spreadsheet functions

RAND() returns a $\mbox{U}[0,1]$ random variable.

COUNTIF($A$5:$A$1005,"=96") counts the number of cells in the range$A$5:$A$1005 which equal the value 96

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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.

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