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Unformatted text preview: wing conclusions based on data. Population: Collection of all elements to be studied. Census: Data from every member of a population. Sample: Subcollection of members from a population. Parameter: Numerical measurement of characteristic of a population. Statistic: Numerical measurement of characteristic of a sample. Random Sample: Every member of population has same chance of being selected. Simple Random Sample: Every sample of same size n has the same chance of being selected. Normal Distribution
Continuous random variable having bell-shaped and symmetric graph and defined by specific equation. Standard Normal Distribution: Normal distribution with m = 0 and s = 1. x-m Standard z score: z = s Central Limit Theorem: As sample size increases, sample means x approach normal distribution; s m x = m and s x = q q 1n x - mx q so that z = s 1n Normal Approximation to Binomial: Requires np Ú 5 and nq Ú 5. Use m = np and s = 1npq. Confidence Intervals (Using Two Samples)
Two Proportions: N N N N 1 p1 - p22 - E 6 1 p1 - p22 6 1 p1 - p22 + E where E = za>2 NN p1q1 NN p2q2 n2 Common Critical z Values
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- Spring '10