Ohio University Module 7 Week 5 Sample Standard Deviation Formula Worksheet Description instructions Instructions If the question requires computatio

Ohio University Module 7 Week 5 Sample Standard Deviation Formula Worksheet Description

instructions

Instructions

If the question requires computation, do the calculations and then give or select the correct values using the following rule:

Keep at least 4 decimal places at intermediate steps of a calculation, and round your final answer to 2 decimal places, unless otherwise noted.

For example:
16.6667 would become 16.67 after rounding

(In the course notes for Module 7, probabilities such .678934 are instead rounded to four decimal places, so the correct way to report the aforementioned probability is .6789)

A sample of data has a standard deviation of 29. If you were to multiply all of the scores in the data set by factor (or constant) of 97, what would the new standard deviation be?

(Hint: The “Working with Constants in Equations” document under Instruction Materials will be helpful to you in answering this question.)

The standard deviation for the sample consisting of 33, 37, and 54 is

On a comprehensive final exam, the mean of the class exam scores was 549, and the standard deviation of the scores was 32. One particular student’s z-score was 3. What was this student’s raw score?

In a negatively skewed distribution, Alisha scored the mean, Ken scored the median, and Catherine scored the mode. Who had the highest score?

Alisha

Ken

Catherine

All three scored approximately the same

A sample of data has a standard deviation of 29. If you were to multiply all of the scores in the data set by factor (or constant) of 97, what would the new standard deviation be?

(Hint: The “Working with Constants in Equations” document under Instruction Materials will be helpful to you in answering this question.)

The standard deviation for the sample consisting of 33, 37, and 54 is

On a comprehensive final exam, the mean of the class exam scores was 549, and the standard deviation of the scores was 32. One particular student’s z-score was 3. What was this student’s raw score?

In a negatively skewed distribution, Alisha scored the mean, Ken scored the median, and Catherine scored the mode. Who had the highest score?

Alisha

Ken

Catherine

All three scored approximately the same

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

2 7
3 4
8 5
0 7

What is the covariance?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

5 1
0 6
8 8
8 4

What is the standard deviation of the predictor variable?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below. (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

0 0
1 7
3 8
2 5

What is the standard deviation of the criterion variable?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below. (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

0 9
7 2
9 7
2 1

What is the Pearson’s r value?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below. (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

0 2
2 8
3 0
8 7

What is the numeric value of the slope (b)?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below. (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

7 0
5 0
9 1
6 9

What is the numeric value of the y-intercept (a)?

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below. (Values below are valid for this question only!)

Stress Score Risk of Heart Attack
(Higher values = more stress) (Higher values = greater risk)

6 9
3 4
3 5
2 8

Set up the regression equation and use to predict the risk of heart attack for a person with a stress score of 2. The risk of heart attack predicted for a person with a stress score of 2 is?

Exam score in Psy 1110 is used to predict nurses’ salaries, and the regression equation turns out to be

ŷ = 7(X) + 300

If a nurse earns a score of 80 on the exam, his/her predicted salary would be $____00.00? (Fill in the blank with the numbers only from solving the regression equation. Do NOT add additional zeros or decimal points.)

(Hint: DO NOT convert 80 to a decimal for this problem! Use the value of 80 (NOT .80) during your calculations.)

Exam score (X) is used to predict nurses’ salaries (ŷ), and the regression equation turns out to be:

ŷ = 6(X) + 398

If a nurse’s predicted salary (ŷ) is $890 per week (for purposes of this problem, represented numerically as 890), what would be his or her exam score (X)?

(Hint: Note that in this particular problem, you are solving for X . . . not for ŷ)

A variable that can be used to predict the value of another variable is called

predictor variable

criterion variable

continuous variable

discrete variable

Which of the following correlations is weakest?

-1

-.5

0

+1

Consider the following sets of variables. When is computing correlation appropriate, based on the type of variables?

Weight and height

Gender (M vs. F) and height

Age category (age category 11-20, age category 21-30, age category 31-40, etc.) and height

Name and height

The direction of causality

Can be determined when two variables have significant linear correlation

Can be determined when two variables have significant nonlinear correlation

Can be determined when two variables have no correlation

Cannot be determined based on correlation alone

In a study of how late people are to work, 64% of the variability of the amount of time late could be accounted for by the time spent in traffic jams. What was the correlation coefficient?

(Hint: See the “Coefficient of Determination” document under Module 5 Instruction Materials.)

The following three questions (Q15 to Q17) are based on the scatterplots below:

If you were to compute a correlation between the X and Y variables for each of the three sets of data, which set of data would yield a correlation closest to zero?

A

B

C

The following three questions (Q15 to Q17) are based on the scatterplots below:

If you were to construct a regression equation using the X variable to predict the Y variable for each of the three sets of data, for which set of data would the regression equation have the largest, positive slope?

A

B

C

The following three questions (Q15 to Q17) are based on the scatterplots below:

If you were to construct a regression equation using the X variable to predict the Y variable for each of the three sets of data, for which set of data would the regression equation have the most negative slope?

A

B

C

Let us say, hypothetically, that you found a significant positive correlation between Exposure to TV Violence and Aggressive Behavior. Which of the following might explain this relationship?

Select any and all options that are correct.

Greater exposure to TV violence is associated with less aggressive behavior

Greater exposure to TV violence is associated with more aggressive behavior

Exposure to TV violence and aggressive behavior are totally unrelated

More aggressive behavior is associated with greater exposure to TV violence

A third, unknown variable is causing both aggressive behavior and exposure to TV violence to similarly rise and fall.

Hurrah! You are halfway through the module assignments! Keep up the effort for the second half! To celebrate get a free point by selecting the correct option below!

Yes, I want the one free point!

No, I refuse the one free point!