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# Binomial distribution help? watch

1. the random variable Y has the distribution B(10,0.4). Use the tables to find:

a) P(y is less than or equal to 5)
b) P(Y=2)
c) P(Y<4)
d) P(Y is more than or equal to 6)
2. So have you seen standardisation of normal variables?
3. (Original post by MrMoonmunch)
the random variable Y has the distribution B(10,0.4). Use the tables to find:

a) P(y is less than or equal to 5)
b) P(Y=2)
c) P(Y<4)
d) P(Y is more than or equal to 6)
You look them up in tables.

What exactly is the difficulty?

10 is the population. 0.4 is the chance of Y.

The entry for 5 gives the value of y being less than or equal to 5.

The entry for 2 gives the probability of Y being 0,1, or 2
The entry for 1 gives the probability of Y being 0,1.

A subtraction is then needed to get the probability of Y being exactly 2.

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