Proportion of variance shared by two correlated variables

Assignment Help Basic Statistics
Reference no: EM13921050

1. For each correlation coefficient below, calculate what proportion of variance is shared by the two correlated variables:

a. r = 0.25
b. r = 0.33
c. r = 0.90
d. r = 0.14

2. For each coefficient of determination below, calculate the value of the correlation coefficient:

a. r2 = 0.54
b. r2 = 0.13
c. r2 = 0.29
d. r2 = 0.07

3. Suppose a researcher regressed surgical patients' length of stay (dependent variable) in the hospital on a scale of functional ability measured 24 hours after surgery. Given the following, solve for the value of the intercept constant and write out the full regression equation:

Mean length of stay = 6.5days; mean score on scale = 33; slope = -0.10

4. Using the regression equation calculated in Exercise 3, compute the predicted value of Y (length of hospital stay) for patients with the following functional ability scores:

a. X = 42
b. X = 68
c. X = 23
d. X = 10

5. Use the regression equation below for predicting graduate GPA for the three presented cases.

Y′ = -1.636 + 0.793(undergrad GPA) + 0.004(GREverbal) - 0.0009(GREquant) +0.009(Motivation)
Subject undergrad GPA GREverbal GREquant Motivation

1 2.9 560 540 55
2 3.2 550 590 65
3 3.4 600 550 70

6. Using the following information for R2, k, and N, calculate the value of the F statistic for testing the overall regression equation and determine whether F is statistically significant at the 0.05 level:

a. R2 = 0.13, k = 5, N = 120
b. R2 = 0.53, k = 5, N = 30
c. R2 = 0.28, k = 4, N = 64
d. R2 = 0.14, k = 4, N = 64

7. According to the University of Chicago, as men age, their cholesterol level goes up. A new drug (XAB) is being tested to determine if it can lower cholesterol in aging males and at what dose. The data for the first test subject is below:

Dose (mg) 2 3 5 6 8 10
Cholesterol level (mg/dL) 310 124 201 110 52 20

a. Plot the data and include a regression line in StatCrunch. Copy and paste your graph into your Word document for full credit.
b. What is the correlation coefficient r and what does it mean in this case?
c. What is the coefficient of determination and what does it mean in this case?
d. Is there a statistically significant correlation between dose and cholesterol level in this case?
e. What is the predicted cholesterol level for a person taking a dose of 4 mg? What about if they are not taking the drug at all (0 mg)?

Reference no: EM13921050

Questions Cloud

Define the term mesopotamia : An upright stone slab decorated with writing or images, used as a marker or memorial, is a and The term "Mesopotamia" means land
What is the yield on a five year bond : The risk free rate of interest is 2.5%. Inflation is expected to be 1.6% this year, 2% next year and 3% the following years. Assume the maturity risk premium is calculated to be .15x (t-1)% default risk premium is fixed at 1% and liquidity premium is..
Bonds outstanding-the capital gain yield : Hooper Printing has bonds outstanding with 15 years left to maturity. You are entitled to 15 more interest payments since the bonds have an 8% semiannual coupon. Par value at issue is since last year. The capital gain yield last year was +6.25%.
Target capital structure-determine their cost of capital : Bartlett Company's target capital structure is 40% debt, 15% preferred, and 45% common equity. The after tax cost of debt is 6%, the cost of preferred is 7.50%, and the cost of common using reinvesting earnings will be $800,000. You were hired as a c..
Proportion of variance shared by two correlated variables : For each correlation coefficient below, calculate what proportion of variance is shared by the two correlated variables:
Role and responsibilities of the ethics committee : What are the role and responsibilities of the ethics committee in healthcare organizations? What type of conflict could healthcare administrators encounter when trying to manage ethical issues pertaining to business
Descriptive statistics for each variable : Below is computer output from SPSS, the package used in the text.  The table below has descriptive statistics for each variable measured the 5-point scale, with 5 being "Strongly Agree" and 1 being "Strongly Disagree"  (Favorable = "SA or A")
Description of the endocrine or musculoskeletal disorder : A description of the endocrine or musculoskeletal disorder you selected including types of drugs that would be prescribed to patients to treat associated symptoms
Application- diabetes and drug treatments : Application: Diabetes and Drug Treatments, Diabetes is an endocrine system disorder that affects millions of children and adults (ADA, 2011). If left untreated, diabetic patients are at risk for several alterations including heart disease, stroke,..

Reviews

Write a Review

Basic Statistics Questions & Answers

  Statistics-probability assignment

MATH1550H: Assignment:  Question:  A word is selected at random from the following poem of Persian poet and mathematician Omar Khayyam (1048-1131), translated by English poet Edward Fitzgerald (1808-1883). Find the expected value of the length of th..

  What is the least number

MATH1550H: Assignment:  Question:     what is the least number of applicants that should be interviewed so as to have at least 50% chance of finding one such secretary?

  Determine the value of k

MATH1550H: Assignment:  Question:     Experience shows that X, the number of customers entering a post office during any period of time t, is a random variable the probability mass function of which is of the form

  What is the probability

MATH1550H: Assignment:Questions: (Genetics) What is the probability that at most two of the offspring are aa?

  Binomial distributions

MATH1550H: Assignment:  Questions:  Let’s assume the department of Mathematics of Trent University has 11 faculty members. For i = 0; 1; 2; 3; find pi, the probability that i of them were born on Canada Day using the binomial distributions.

  Caselet on mcdonald’s vs. burger king - waiting time

Caselet on McDonald’s vs. Burger King - Waiting time

  Generate descriptive statistics

Generate descriptive statistics. Create a stem-and-leaf plot of the data and box plot of the data.

  Sampling variability and standard error

Problems on Sampling Variability and Standard Error and Confidence Intervals

  Estimate the population mean

Estimate the population mean

  Conduct a marketing experiment

Conduct a marketing experiment in which students are to taste one of two different brands of soft drink

  Find out the probability

Find out the probability

  Linear programming models

LINEAR PROGRAMMING MODELS

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd