Stats III

Question 1

What is a sampling distribution?

Answer 1

Distribution of means of samples

Question 2

What does it mean for a statistic to be an unbiased estimate of a parameter?

Answer 2

equal to population parameter

Question 3

The is the type I (alpha) error?

Answer 3

Accept Ha, reject H0 when H0 is true

Question 4

What is the type II error?

Answer 4

Accept H0 when Ha is true

Question 5

What is the difference between a statistic and parameter?

Answer 5

Parameter = info about whole population

Statistic = info from a sample of a population

Question 6

The standard deviation of the sampling distribution = ?

Answer 6

SD of sampled pop / n^.5

Question 7

What is the standard error of the mean?

Answer 7

Standard deviation of sample of means

Question 8

Standard normal distribution is centered around what? What is the SD?

Answer 8

0

with SD = 1

Question 9

What is a Z score?

Answer 9

Difference between sample mean and population mean, divided by standard error

Question 10

When n is sufficiently large, what are the values of mew(xbar) and sigma(xbar)?

Answer 10

mew(xbar) = mew
Sigma(xbar) = sigma/n^.5

Question 11

What is the equation for calculating a confidence interval?

Answer 11

x(bar) + z(sigma) : z = z score, sigma = SD of sample means

Question 12

90% confident Z score is what?

Answer 12

1.645

Question 13

95% confidence Z score is what?

Answer 13

1.96

Question 14

99% confidence Z score = ?

Answer 14

2.58

Question 15

What is the equation of the margin of error?

Answer 15

Z(sample SD) = SE

Question 16

What is a statistical hypothesis?

Answer 16

Statement about the numerical value of a population parameter

Question 17

What is the difference between testing one vs two tails?

Answer 17

one tail means mew does not equal some value

Two tail means that mew is greater than or less than some value

Question 18

How many samples are used in observational studies?

Answer 18

1

Question 19

How many samples are used in clinical trials?

Answer 19

2+

Question 20

What is a test statistic?

Answer 20

Sample statistic computed from information provided in a sample

Question 21

What is the rejection region?

Answer 21

Area beneath a bell curve where the null hypothesis is true

Question 22

How do you know to reject or accept the null hypothesis?

Answer 22

if p value >= alpha, then do not reject null

Question 23

What is the p value?

Answer 23

The probability of observing a value of the test statistic that is at least as contradictory to the null