UNIT5 Confidence Intervals Flashcards
(11 cards)
Are population meand and sample mean the same thing?
No
What is the confiedence interval for the mean?
Rnage of value within which the population means U lies with a certain probability
What is a confidence limit?
Upper and lower limits of the interval
What is the normal confidence level in chemistry?
95%
As you increase the number of samples, what happens to uncertainty and distribution?
Reduction of uncertainty and distribution
__ CI in more precise
Smaller
What is the significance level of the confidence interval is 95%?
5%
When do you use t and z test?
t- small sample <20
z- large sample >20
What do you use to calculate an outlier?
Qtest
When can you reject an outlier?
Q>Qcrit
If there is retention with the Q test, what is the better center to use?
Median