1. Umm Al-Qura University
بسم الله الرحمن الرحيم
Umm Al-Qura University
Health Sciences College at Al-Leith
Department of Public Health
Lecture (6)

2. Probability Distributions
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3. Objectives: 1/ Define basics of Probability Distributions.
2/ Define Types of Probability Distributions.
2/ Give an Example of Probability Distributions.

4. The Binomial Distribution
Discrete
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5. The Binomial Probability Distribution p = P(S) on a single trial
q = 1 – p
n = number of trials
x = number of successes
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6. statistic

7. Say 40% of the class is female.
What is the probability that 6 of the first 10 students walking in will be female?
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8. The Binomial Distribution
Mean
Variance
Standard Deviation
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9. Bernoulli Distribution
Discrete
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10. Bernoulli Distribution it special case from Binomial Distribution ( n =1)
f(x) = px (1-p)1-x,    for x = 0, 1
μX = E(X) = np = p
n=1
μX =p
σ2X = Var(X) = np(1−p)
n=1
σ2X = Var(X) = p(1−p)
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11. Coin , p(H) = 0.4 and p(T) = 0.6 Find X ~ Bernoulli (0.6) μX =p = 0.6
σ2X = Var(X) = p(1−p) = 0.6*0.4 = 0.24
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12. Normal Distribution
Continuous
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13. X ~ N(μ,σ2)
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14. Calculating Probabilities for Standard Normal Distribution
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15. If the length of one of the tribes are distributed naturally by average (165cm) and standard deviation (5cm) Find the standard value (z), where x= 172 , and value (x) if z= ?
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16. End
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