Section 6 (Pgs 68-80)

Question 1

If the probability off successes at each binomial trial is p and number of trials is n, what does the mean number of successes equal?

Answer 1

np

Question 2

If the probability of successes at each binomial trial is p and number of trials is n, what does the variance equal?

Answer 2

np(1-p)

Question 3

If the probability of successes at each binomial trial is p and number of trials is n, what does the sample population proportion equal?

Answer 3

p

Question 4

If the probability of successes at each binomial trial is p and number of trials is n, what does the sample standard error equal?

Answer 4

square root of p(1-p)/ n

Question 5

Under what conditions can inferences about the number of successes, and the population proportion, be based on the normal distribution sampling theory?

Answer 5

when np and n(1-p) are both greater than 5

Question 6

For a hypothesis test of binomial proportion, what 2 options can the test be based on?

Answer 6

The number of successes

The proportion of successes

Question 7

What does regression analysis do?

Answer 7

Provides information about the nature of the relationship and enables predictions to be made

Question 8

What does correlation technique do?

Answer 8

Assesses the linear relationship between 2 continuous variables

Question 9

What technique is used to assess relationships between categorical variables?

Answer 9

Chi squared techniques

Question 10

What technique is used to assess relationships when one variable is categorical?

Answer 10

Logistic regression

Question 11

What is the word used to described when one set of continuous data changes proportionally with another?

Answer 11

Correlated

Question 12

What measurement is used to describe the strength of the linear relationship between 2 continuous variables?

Answer 12

Correlation coefficient

Question 13

What range of values can the correlation coefficient be between?

Answer 13

-1 and +1

Question 14

What does the sign of the correlation coefficient indicate?

Answer 14

The direction of the relationship

Question 15

What does the magnitude of the correlation coefficient indicate?

Answer 15

The strength of the relationship

Question 16

If there is no linear association, what would the value of the correlation coefficient be?

Answer 16

0

Question 17

Approximate value of the correlation coefficient if there is no correlation?

Answer 17

0-0.1

Question 18

Approximate value of the correlation coefficient if there is a very weak positive correlation?

Answer 18

0.1-0.2

Question 19

Approximate value of the correlation coefficient if there is a weak positive correlation?

Answer 19

0.2-0.4

Question 20

Approximate value of the correlation coefficient if there is a moderate positive correlation?

Answer 20

0.4-0.7

Question 21

Approximate value of the correlation coefficient if there is a strong positive correlation?

Answer 21

0.7-1.0

Question 22

How would you describe it when there is a close relationship between the 2 variables with a large value of one variable being associated with a large value of the other?

Answer 22

Strong positive linear correlation

Question 23

How would you describe it when the 2 variables cluster less closely around the line with a large value of one variable being associated with a large value of the other?

Answer 23

Moderate positive linear correlation

Question 24

How would you describe it when there is a close relationship between the 2 variables with a large value of one variable being associated with a small value of the other?

Answer 24

Strong negative linear correlation

Question 25

What is the full name of the correlation coefficient?

Answer 25

Pearson's product moment correlation coefficient

Question 26

What is the symbol for Pearson's product moment correlation coefficient?

Answer 26

r

Question 27

What is the initial steps in investigating relationships?

Answer 27

Produce a scatter plot

Question 28

Does a mathematical relationship between 2 variables imply cause and effect?

Answer 28

No

Question 29

Can correlation be used to measure agreement?

Answer 29

No

Question 30

What happens to the value of r as sample size increases?

Answer 30

Value of r increases

Question 31

What 3 conditions must be met for the significance of an observed value of r to be determined from tables?

Answer 31

At least one variable is plausibly normally distributed (preferably 2) Measured on a random sample Pairs of variables are independent

Question 32

How can you tell if both variables on a scatter plot are normally distributed?

Answer 32

Scatter plot is elliptical

Question 33

Does a mathematically significant correlation mean it is clinically significant?

Answer 33

No

Question 34

What does r squared measure?

Answer 34

The proportion of the variation in the dependent variable (y) which is attributable to its linear relationship with the independent variable (x)

Question 35

How is r squared dependent on the number of observations in the sample?

Answer 35

Independent of the number of observations

Question 36

How should correlation be used to explore data?

Answer 36

Correlation should only be used to investigate specific hypothesis about relationships

Question 37

Can correlation be used to measure agreement?

Answer 37

No - as agreement is comparing 2 values assessing the same quantity there is sure to be some sort of agreement

Question 38

What can be plotted if there is a significant linear association between two variables?

Answer 38

The line of best fit

Question 39

What is the general form of the regression line?

Answer 39

y = a + bx

Question 40

What word can be used to describe a and b?

Answer 40

Constants

Question 41

What is a?

Answer 41

The intercept

Question 42

What is b?

Answer 42

The slope

Question 43

What is the intercept?

Answer 43

The value of y when x=0

Question 44

What is the slope?

Answer 44

The change in y when x increases by one unit | change in y/ change in x

Question 45

What 3 assumptions are being made when regression methods are used?

Answer 45

The correlation between x and y variables is significant For each value of the x variable, the values of the y variable have a normal distribution The variances of these normal distributions are equal

Question 46

Can the regression equation be used for values of the independent variable not increased in the sample range?

Answer 46

No