stats exam
Random sample
sample in case wich every person was selected from population with equal degree of probability
Biased sample
a sample in wich a portion of the population where a sertine segment of the population is over represented
Research sample
trying there best to be random sample but aware of there flaws
expected value
the mean of a sampling distribution
standard error
the standard deviation of the sampling distribution
what central limit theorem
< sample size sampling distribution it will get closer to normal distribution
Sample statistics
sample means should group around the mean
what T distribution
it estemation for sample divation for small samples that might not be completely accurate
what are degrees of freedom in t-distribution
N-1
what is the problem with small degrees of freedom
too platykurtic / flat
populaion mean is
is if sample mean is with in donfidence intervals
what is the acseptibe error
5%