Chapter 8: Sampling Distributions Flashcards
parameter
numerical summary of the population
statistic
numerical summary of a sample
sampling distribution
probability distribution for all possible values of the statistic computed from the sample size n
sampling distribution of the mean x̄
probability distribution of all possible values of the mean x̄ of a sample with size n
What is the mean of the sampling distribution of x̄?
μ_x̄ = μ_x
What is the standard deviation of the sampling distribution of x̄?
σ_x̄ = σ_x/sqrt(n)
central limit theorem
regardless of the shape of the original population, the sampling distribution of x̄ becomes approximately normal as the sample size n increases
What does n have to be for the central limit theorem to be satisfied?
n ≥ 30
sample proportion
proportion of individuals from the sample that has a certain characteristic
What is the formula for sample proportion?
p̂ = x/n
sampling distribution of p̂
probability distribution for all possible values of p̂ from the sample size n
What is the mean of the sampling distribution of p̂?
μ_p̂ = p
What is the standard deviation of the sampling distribution of p̂?
σ_p̂ = sqrt(pq/n)
What are the conditions for the sampling distribution of p̂ to be normal?
npq ≥ 10 and 20n ≤ N