18 Flashcards
Confidence level in words?
The chance that the procedure will do the right thing.
Assumptions for the confidence interval for a mean z interval? 2*
*Population distribution is normally distributed with known variance sigma^2
*Random sample of size n has been collected.
The confidence interval when assumptions about the data are correct?
The chance that the procedure was true is close to the confidence level.
Critical value?
Look at the distribution and get the area that corresponds to what is inside alpha and the graph
Is it possible to find the variance of a sample mean?
Alternative assumptions of 1-mean, T-interval.
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!!!
•Seomthign normal
•Not extremely skewed
If you were to repeat a procedure with a high confidence interval, where alpha = 0.05?
You are most likely 95% confidence that the specific data will be shown.
What jumps around, the parameters or the guesses?
The guersses move around.
If n is going to be big, then the normal and the t distribution will be?
Almost the same picture
Confidence interval for the proportion of successes (successes or failures without knowing the proportion of successes)?
The more confident you want to be, do you need a bigger/smaller sample size?
Bigger.
Two assumptions for confidence interval for a proportion of success? 2•
•Population is partitioned into two mutually exclusive and exhaustive subsets labeled successes and failures within unknown proportions of successes
•and random sample of size n has been collected such that the number of successes and number o failures within the sample are both at least 10.
When trying to find the confidence interval for proportion p of successes, why can we not use p?
Since p is not known and needs to be guessed.
Assumptions when finding confidence interval for 1 mean t-interval?
*Probability distribution is normal
*Unknown variance
*random sample size n collected where n large enough for CLT.
The degree of freedom in t distribution depends on?
sample size
