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प्रश्न
In a particular university 40% of the students are having newspaper reading habit. Nine university students are selected to find their views on reading habit. Find the probability that all those selected have newspaper reading habit
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उत्तर
Let p to the probability of having newspaper reading habit
p = `40/100 = 2/5`
q = 1 – p
= `1 2/5`
= `(5 - 2)/5`
= `3/5` and n = 9
In the binomial distribution p(x = 4) = ncx pxqn-r
The binomial distribution P(x) = `9"C"_x (2/5)^x (3/5)^(9 - x)`
P(all those selected have newspaper reading habit)
= `"P"("X" = 9)`
= `9"C"_9 (2/5)^9 (3/5)^(9 - 9)`
= `(1)(2/5)^9 (3/5)^0`
= `(2)^9/(5)^9`
= `512/1953125`
= 0.000262
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