Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Marketing Research > Midterm 2 > Flashcards

Midterm 2 Flashcards

1
Q

Rectangle shaped probability distribution is called:

A

UNIFORM distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The symbol u represents?

A

Population Mean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the symbol s^2 represent?

A

Sample variance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A bell-shaped curve is called:

A

A NORMAL Distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does a z-score indicate?

A

How many standard deviations from the mean an observation is located.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many standard deviations is the 95% confidence limits from the mean?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why are normal distribution so important?

A

Many dependent variables are commonly assumed to be normally distributed in the population and if a variable is approximately normally distributed we can make inferences about the values of that variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The total area under any curve is?

A

One.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sample size formula:

A

Z^2
N=—— (s^2)
H^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sample size formula-proportion:

A

Z^2
N=——% of pop(1-% of pop)
H^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Variance:

A

How dispersed the data is.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a synonym for average and how do you find it?

A

Mean; add all the values and divide by the number of observations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a cross tabulation?

A

A statistical process that summarizes categorical data to create a contingency table.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Assuming there is no relationships between variables is called what?

A

The null hypothesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do we find the expected value per cell?

A

(Column X Row) / Total

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does a chi-square test measure?

A

How much variation there is in each cell of the table.

17
Q

Chi-Square:

A

(Obs-Exp)^2/Exp

18
Q

How do you calculate the degrees of freedom?

A

(# of rows -1) x (# of columns -1)

19
Q

Decision Rule:

A

If test statistic> critical value
reject the null
If test star

20
Q

What is a t-test?

A

Is statistic that checks if two means our reliably different from each other.

21
Q

What are descriptive statistics?

A

Statistics that describe the data that you have such as the mean but cannot generalize beyond that.

22
Q

What are inferential statistics?

A

Statistics like t-test for chi-squared test that allow us to make inferences about the population beyond our data.

23
Q

How does a t-test work?

A

It is the variance between the groups divided by the variance within the groups.

24
Q

What is a P value?

A

The P value is the probability that the pattern of the data could be produced by chance that is random data.

25
Q

What is a good guideline to have between four sample size data points?

A

20 and 30+ data points in each group.

26
Q

What types of t-test are there?

A

Independent samples, paired samples, and one sample.

27
Q

Independent samples test what?

A

They compare the means of two different groups.

28
Q

What do you paired sample t-test test?

A

They compare the means of one group twice before and after.

29
Q

What does a one sample t-test test?

A

The mean of one group against some other value example IQ.

30
Q

What are the limitations of t-tests?

A
  1. The results of inferential statistics can only be applied to populations that resembled the sample that was tested.
  2. Your sample and population should be roughly normal in their distribution though the test is robust.
31
Q

What are the last two limitations of t-tests?

A
  1. You should have roughly similar sized groups.

4. All data should be independent.

32
Q

The alternative hypothesis states:

A

There is an association between variables.

33
Q

What is the significance level associated with the 95% confidence interval?

A

The .05 significance level.

34
Q

The Dependant variable in any test is?

A

What is changing and can be measured.

35
Q

Null hypothesis in symbols:

A

Ho: u(before)-u(after) = 0

36
Q

How can you tell whether there was a change in variables or not if you’re jump printout was not readable?

A

If there is a zero between the upper 95% in the lower 95%.

37
Q

Histograms allow us to examine?

A

The DISTRIBUTION of a variable.

Marketing Research (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions