A number is selected at random from the numbers 3, 5, 5, 7, 7, 7, 9, 9, 9, 9 The probability that the selected number is their average is

Total numbers of elementary events are: 10

Let E be the event of getting selected number being the average


Favorable outcome is = 70 /10 = 7


Average = total of observations/ numbers of observation


Total of observations = 3+ 5+ 5+ 7+ 7+ 7+ 9+ 9 + 9+ 9 = 70


Numbers of observation = 7


Numbers of favorable outcomes are: 3


P ( selecting average number) = P (E) = 3/10

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