If a researcher matches subjects between groups the

appropriate t-test is the t-test for - - - - -

Which of the following can take on a value of -0.5?

What is

the main difference between a z-test and a t-test when a single sample test for

a mean is performed?

A group of middle managers in a

company are required to undergo a training programme aimed at improving their

leadership abilities. A researcher wants to establish the effectiveness of the

training programme. She tests each participant before the training commences on

a questionnaire that measures the leadership ability of each participant as

well as on their score on a scale that measures self-esteem. After the training

programme is completed, each participant is again tested for their leadership

ability.  The table below shows the

results of the measurements.

Key:

The variable Gender is coded with 1 = Male; 2 = Female.

SelfEst

is a variable indicating self-esteem and was measured on a 5-point

scale (ranging from 1=’low self-esteem’ to 5=’high self-esteem’).

The researcher is also interested

to determine whether a relationship exists between self-esteem and leadership

ability before the training programme. 

Which of the following is the most appropriate test statistic to use?

A researcher suspects that children’s level of anxiety during a test

will interfere with their memories.  He

gives a list of items to be memorized to a sample of children, and gives them a

test to see how many items they can remember. Directly afterwards he also tests

the level of anxiety of each child with an anxiety scale (where higher score

shows a greater level of anxiety).

The researcher draws a scatter plot of the relationship between level of

anxiety and number of items recalled. The result is presented below.

Suppose the researcher uses the data to calculate the Pearson

product-moment correlation (r) coefficient to determine the size of the

relationship between

Which of the following would be most probable as description of r?

(Which of following descriptions of the expected value of r seems to be the

most appropriate?)

A researcher suspects that children’s level of anxiety during a test

will interfere with their memories.  He

gives a list of items to be memorized to a sample of children, and gives them a

test to see how many items they can remember. Directly afterwards he also tests

the level of anxiety of each child with an anxiety scale (where higher score

shows a greater level of anxiety).

The researcher draws a scatter plot of the relationship between level of

anxiety and number of items recalled. The result is presented below.

What can the researcher infer about the relationship between level of anxiety and number of items remembered

from the

graph presented above?  There is - - - -

-.

Suppose you find that the value of the t-statistic calculated for your research results is zero.  Which conclusion is appropriate?

A negative correlation between variables X and Y implies that persons

scoring low on X will generally score - - - - - on Y.

The following list contains a number of situations where a researcher

may consider using a variation of the t-test:

(a)       To compare two group means

(b)      

To determine whether a relationship exists between two categorical

(nominal scale) variables

(c)       To compare a group mean with a constant value

(d)      

To determine whether a relationship exists between two continuous

quantitative variables

Two of the statements above are true. Choose the correct set of true

statements from the list below:

The higher we set the level of significance, the greater the probability of - - - - -.