Inferential statistics and hypothesis testing

Question 1

if the sampling distribution of a sample statistic has a mean equal to the population parameter that the statistic is intended to estimate, what is said of the statistic?

Answer 1

it is an unbiased estimate of the parameter

Question 2

if the mean of the sampling distribution is not equal to the parameter, what is said of the statistic?

Answer 2

it is a biased estimate of the parameter

Question 3

what is the standard deviation of the sampling distribution?

Answer 3

standard deviation of sampled population / square root of sample size

(sampling error)

Question 4

what are the two types of inferential statistics?

Answer 4

1. estimation

2. hypothesis testing

Question 5

definition: confidence interval

Answer 5

provides a range of plausible values for the population parameter

Question 6

what are the conditions required for a valid confidence interval for u?

Answer 6

1. random sample

2. large sample size

Question 7

when do you use Student’s t statistic?

Answer 7

when you do not know what the standard deviation of the population is

Question 8

what is the main difference between the sampling distributions of t and z?

Answer 8

t statistic is more variable than the z statistic

Question 9

what is described by degrees of freedom?

Answer 9

actual amount of variability in the sampling distribution

Question 10

how is the reliability associated with a confidence interval for the population mean expressed?

Answer 10

sampling error (margin of error)

Question 11

definition: type I error

Answer 11

occurs if researcher rejects the null hypothesis in favor of the alternative hypothesis when in fact the null hypothesis is true

denoted by alpha

Question 12

definition: type II error

Answer 12

occurs if the researcher accepts the null hypothesis when, in fact, the null hypothesis is false

denoted by beta

Question 13

definition: p value

Answer 13

observed significance level for a specific statistical test is the probability of observing a value of the test statistic that is at least as contradictory to the null hypothesis, and supportive of the alternative hypothesis, as the actual one computed from the sample data

Question 14

the p value is compared to what other value when determining whether or not to reject the null hypothesis?

Answer 14

alpha (type I error value)

Question 15

what conditions are required for a valid hypothesis test for u?

Answer 15

1. random sample

2. large sample size

Question 16

when determining confidence, is the confidence in the testing process or the result of a single test?

Answer 16

testing process