CLT

Question 1

standard deviation is also known as?

Answer 1

how spread out the sampling is

Question 2

Central Limit Theorem?

Answer 2

Sampling distribution of x w/ a hat

Question 3

standard deviation of x w/ a hat=

Answer 3

standard error (SE)

Question 4

what does the standard error represent?

Answer 4

standard deviation of the sample mean
-sigma/square root of n OR sd/square root of n
Ex: waist to height ratio: 0.63+-0.06 (N=2454) 0.06/sq root of 2543=

Question 5

what is a confidence interval?

Answer 5

refers to the probability that a pop. parameter will fall between a set of values for a certain proportion of times
-xbar +- critical value (z)*SE (s/square root of n)
-with a 95% CI, you have a 5% chance of being wrong

Question 6

critical value?

Answer 6

the area outside the confidence interval on both sides
-look at a CI graph
-the spaces on the outside

Question 7

degrees of freedom?

Answer 7

sample size-1
Ex: if my sample size=6, the dof is n-1=5
-degrees of freedom=5