Mini test 4 stats

when selecting a sample out the population what should one be considerin? (2 things)

The sampiling distrubution and its ahpe and sample size

if the sample is not normal sample size must be greater than 30 to be considered approxmently normal

The parameters of sampling distriubtion are the mean and standerd deviation sometimes the standard devitation needs to be adjusted by a corretion factor, when would this NEED to happen

when sampiling without replacement and the sample size is greater than 5%

What are the assumptions for the z interval (3)

1) sample is a simple random sample

2) sample size is 30 or more or comes from a normal population

3) population standerd deviation is known

s

what is the assumption for the t interval (3)

1) sample is a simple random sample

2) sample size is 30 or larger the sample comes from a normal population

3) pop standard devitation is unknown

how could one decrease a margin error

1) increase sample size

2) lower the level of confidence