Q12 of 99 Page 33

In eight throws of a die 5 or 6 is considered a success, find the mean number of successes and the standard deviation.

Let p be the probability of success


∴ the p = probability of getting 5 or 6




Given, n = 8


Mean = np



= 2.66


Standard deviation =




= 1.33


Therefore, mean = 2.66, standard deviation = 1.33.


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