Unit 5 - Sampling Distributions

effects of changing sample size (NB 1 pg 85); confidence intervals and equation (NB 1 pg 88); effects of changing confidence interval (NB 1 pg 90); margin of error and equation (NB 1 pg 93); sample size's effect on width of interval (NB 1 pg 95); z-scores of confidence levels (NB 1 pg 90)

A __________ sampling distribution is a graph of all possible samples from a population

theoretical

In a theoretical sampling distribution graph, the ______ always lands at the ____ proportion/mean/slope.

center, true

In a theoretical sampling distribution graph: as sample size increases, the distribution becomes more symmetrical like what kind of distribution?

normal

In a theoretical sampling distribution graph: as sample size increases, the ______ decreases.

spread

What conditions need to be checked before calculating the confidence interval? (4)

randomization, independence, 10 successes/failures, sample 1/10 of population size

A 90% confidence level, for example, means that if repeated samples are taken, 90% of them will contain the ____ proportion/mean/slope of the population.

true

Increasing the confidence level results in a ______ z-score and a _____ interval

higher, wider

Decreasing the confidence level results in a ______ z-score and a _____ interval

lower, narrower

Tells how far above/below the true proportion extends past the sample proportion (aka point estimator)

margin of error

When a sample size is multiplied by n, the width is divided by the ______ ____ of n.

square root

Confidence interval equation: p =

p-hat ± z√((p-hat*q-hat)/n)

confidence level of 90% has a z-score of:

±1.645

confidence level of 95% has a z-score of:

±1.96

confidence level of 99% has a z-score of:

±2.576