Stats exam 3 vocabulary Flashcards
Point Estimate
is the sample statistic estimating the population
parameter of interest (sample mean or sample proportion)
Critical Value
is a table value based on the sampling
distribution of the point estimate and the desired confidence
level.
Standard of error
(standard error of mean or proportion)
when do you use degrees of freedom
when the standard deviation is a estimate
What is point estimate
WHat you are aiming to find
DO you hope to get a wide or narrow interval
For a high level of confidence you hope for a narrow interval.
If you want a higher level of confidence
You have to accept a wider interval
WHy is larger sample size vunerable
you get a narrower interval because standard error is lower
hypothesis
A clain about a population parameter
Null Hypothesis
States the claim or assertion needs to be tested
How do you evaluate the Null
We reject or do not reject the null
Alternative Hypothesis
The opposite of the null hypothesis
True or False: It is possible that the confidence interval you calculated in question #6 will not contain the mean score for all actuarial students in the special study program.
true
True or False: For the confidence interval you calculated in question #6 to be valid, it is necessary that population test scores of students in the special study program be normally distributed.
true
Holding the level of confidence fixed, increasing the sample size will lead to a wider confidence interval
false
The t-distribution is especially important when analyzing
A mean from a very small sample
The width of a confidence interval estimate for a proportion will be
narrower for 90% confidence than for 95% confidence
A Type II error is committed when
you don’t reject a null hypothesis that is false
A Type I error is committed when
you reject a null hypothesis that is true.
The power of a test is measured by its capability of
rejecting a null hypothesis that is false
f the p-value is low, the null must go.
True
If the p-value is less than alpha (the level of signficance) in a two-tail test,
the null hypothesis should be rejected.
If we are testing for the difference between the means of 2 independent populations presuming equal variances with samples of n1 = 20 and n2 = 20, the number of degrees of freedom is equal to
38
A statistics professor wanted to test whether the grades on a statistics test were the same for juniors and seniors. The professor took a random sample of 10 juniors and a random sample of 10 seniors. For this situation, the professor should use a paired t test for related samples.
False
