Final Flashcards Preview

Stats > Final > Flashcards

Flashcards in Final Deck (44):
1

Critical value

First value for which we would reject the null hypothesis

2

If p-value is less than or equal to alpha(significance level)

Then we reject the null hypothesis

3

Sentence if u reject the null

We reject the null hypothesis and conclude the alternative hypothesis is true. The results of our sample are statistically significant

4

Failing to reject null

We fail to reject the null hypothesis and conclude the alternative is false. The results of our sample are not statistically significant. There is not sufficient evidence against the null hypothesis

5

Type 1 error

The null hypothesis is true, but we mistakenly reject it
Alpha

6

Type 2 error

The null hypothesis is false, but we fail to reject it
Beta

7

Power depends on effect size. The larger the effect size,

The greater the power of the test

8

Power of the test

1-Type 2 error(beta)
The tests ability to detect a false hypothesis

9

Effect size

Distance between the null value and the true parameter

10

How to describe confidence interval

We are blank % confident that the true proportion of (subject) is captured within the interval

11

Confidence interval

Represents success rate of the method used to construct the interval

12

Confidence intervals for proportions are based on

Point estimate and margin of error

13

4 requirements for confidence interval to be valid estimate

1.np>10, nq>10
2.sample size is less than 10% of pop, of sampling without replacement
3. Sample can be regarded as a simple random sample
4. Data values are assumed to be independent of each other

14

In order to decrease the margin of error for greater precision we should

1. Decrease the confidence level
2. Increase the sample size

15

Describe confidence interval for population mean

We are blank% confident that the true mean of (subject) is captured within the interval

16

T values account for

Confidence level

17

In order for a confidence interval to be valid what must u assume about its graph

Bell shaped + other stuff

18

For a sampling distribution model for a sample mean, as sample size increases the mean

Of our sample will stay the same

19

Taking the average of larger sample sizes gives a more or less precise estimate of the true mean, thus the spread around the center gets smaller or larger

More precise, gets smaller

20

The central limit theorem(CLT)

Draw a simple random sample of size n(>30) from any non-normal population with a mean and a standard deviation, then the sample mean has a sampling distribution that is approximately normal as long as the sample is large enough.

21

For CLT to be applicable the sample values must be

Independent of one another

22

A categorical parameter that describes the difference in 2 population proportions

P1-p2

23

Quantitative parameter that describes the population mean of paired differences(dependent samples)(matched pairs)

(Sigma)d or Xd(for a sample)

24

Quantitative parameter that describes the difference in 2 population means for independent samples(drug trials)

Mean1-mean2

25

Use t distribution table when working when the blank is unknown

The population standard deviation signs

26

Cumulative probability

P(Xa)

27

Use a binomial model when

NP<10

28

Binomial sampling distribution

X~B(n,p)
N=total sample
P=proportion

29

nCk by hand

N/(k)(n-k)

30

Binomial mean

Np

31

Binomial standard deviation

Square root(np(1-p))

32

Variance for binomial

Npq

33

Normal approximation for a binomial distribution

X~AN(mean=np,sigma=square root (npq)

34

Standard deviation of the sample mean

Sigma(population standard deviation)/square root(n)

34

Standard deviation of a sample proportion

Square root (pq/n)

35

Standard error of sample proportion

Square root of [sample (pq)/n)]

36

Margin of error general formula

Z*SE(sample p)

37

Standard error of sample mean

S/Square root(n)

38

If you know the standard deviation of the sample mean then which test statistic do you use

Z score

39

If you know the standard error of the sample mean then which test statistic do you use

T score

40

Mu(u) symbolizes

Population mean

41

Ud symbolizes

Population mean of paired differences(matched pairs)

42

Difference in 2 pop means for independent samples

U1-U2

43

s symbolizes

Sample standard deviation