STATISTICAL TECHNIQUES AND TOOLS
SAMPLING DISTRIBUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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n ≥ 30
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the population is normal
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either np or nq is ≥ 30
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np and nq are both ≥ 10
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Detailed explanation-1: -The Sampling Distribution of the Sample Proportion. For large samples, the sample proportion is approximately normally distributed, with mean ˆP=p. and standard deviation ˆP=√pqn. A sample is large if the interval [p−3ˆp, p+3ˆp] lies wholly within the interval [0, 1].
Detailed explanation-2: -1) if random samples of size n, where n is greater than or equal to 30, are drawn from any population with a mean and a standard deviation, then the sampling distribution of sample means approximates a normal distribution. The greater the sample size, the better the approximation.
Detailed explanation-3: -10 Percent Rule: The 10 percent rule is used to approximate the independence of trials where sampling is taken without replacement. If the sample size is less than 10% of the population size, then the trials can be treated as if they are independent, even if they are not.