BINOMIAL EXPANSION

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BINOMIAL EXPANSION
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BINOMIAL DISTRIBUTION
2 things can happen. Success (p) and Failure (q)
Binomial think of an Archer shooting he can hit
P(0.7) or miss P(0.3)
What is the probability that in 4 shots he hits 0
times, once, twice etc?
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YOUR TURN
Different Archer - she can hit P(0.2) or miss
P(0.8)
What is the probability that in 5 shots he hits 0
times, once, twice etc?
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FORMALISED
XB(n,p) n number of trials p probability of
success
Conditions 1) the number of trials must be
fixed 2) Trials must be independent 3) Trials can
only have two outcomes 4) Probability of success
in constant between trials
p success q failure n no. of trials r no.
of success asked for
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EXAMPLE
The probability of an archer hitting a target is
0.4. Assuming a binomial distribution find the
probability that he hits the target 8 times out
of 10