Card Set Information
mue w.o st.deviation
Estimated St. Error
is an estimate of the st. error of the sampling distribution of the M.
Est. St. Error of the Sampling Dist of M
sample st.deviation / square root of n
t statistic is
formed whenever a statistic has a normal sampling distribution (M) is transformed by subtracting the mean of the sampling distribution and dividing by est of the st error (sample)
Comparison of t and z distrib
1. t and z both have means that equal 0
2. t and z both have distributions that are symmetric about the mean.
3. t dist are more variable than the z
4. Shape of a t changes with sample size
Degrees Of Freedom
is the number of degrees of freedom for a statistic equals the number of components in it's calculation that are free to vary. so, 1/5 are fixed and 4/5 are free to vary. n-1
a statistic is robust if it gives fairly accurate results even when an assumption is violated.
is used to locate power.