Concept explainers
Videos
(a)
To find out what type of design did the researchers use in their study.
(a)
Answer to Problem 80E
Matched pair design.
Explanation of Solution
In this study, the researcher wanted to test if chocolate affects blood vessel function or not. So, they recruited healthy young volunteers to examine this and each of the volunteers goes through both of the treatments i.e. they were give both bittersweet chocolate and the fake chocolate.
Thus we can say that, the design used for this experiment is matched pair design, since each subject is administered both treatments in a random order and compared to themselves.
(b)
To explain why the researcher choose this design instead of completely randomized design.
(b)
Explanation of Solution
In this study, the researcher wanted to test if chocolate affects blood vessel function or not. So, they recruited healthy young volunteers to examine this and each of the volunteers goes through both of the treatments i.e. they were give both bittersweet chocolate and the fake chocolate.
The researcher choose matched pair design instead of completely randomized design because matched pair design helps eliminate variability among subjects by comparing each subject's response to treatment A with their own response to treatment B.
Thus, this design uses the same subjects for both groups which means that the result will be easier to compare.
(c)
To explain why it is important to randomly assign the order of the treatments.
(c)
Explanation of Solution
In this study, the researcher wanted to test if chocolate affects blood vessel function or not. So, they recruited healthy young volunteers to examine this and each of the volunteers goes through both of the treatments i.e. they were give both bittersweet chocolate and the fake chocolate.
It is important to randomly assign the order of the treatments because if all the subjects first receive the bittersweet chocolate then they might recognize that the second chocolate is fake. Thus, it is better to receive the bittersweet chocolate first and that some receive the fake chocolate first.
(d)
To explain how and why the researchers controlled for other variables in this experiment.
(d)
Explanation of Solution
The researchers controlled for other potential health issues by choosing young, healthy volunteers. They also controlled against chocolate consumption outside of the confines of the experiment.
Other potential health issues were controlled because other health issues may be responsible in differences between blood vessel function as opposed to chocolate. Additionally, outside chocolate consumption was controlled to ensure that a placebo subject did not have real chocolate and skew the results of the experiment.
Chapter 4 Solutions
PRACTICE OF STATISTICS F/AP EXAM
Additional Math Textbook Solutions
Calculus: Early Transcendentals (2nd Edition)
A First Course in Probability (10th Edition)
Basic Business Statistics, Student Value Edition
Elementary Statistics: Picturing the World (7th Edition)
University Calculus: Early Transcendentals (4th Edition)
A Problem Solving Approach To Mathematics For Elementary School Teachers (13th Edition)
- The table given shows the length, in feet, of dolphins at an aquarium. 7 15 10 18 18 15 9 22 Are there any outliers in the data? There is an outlier at 22 feet. There is an outlier at 7 feet. There are outliers at 7 and 22 feet. There are no outliers.arrow_forwardStart by summarizing the key events in a clear and persuasive manner on the article Endrikat, J., Guenther, T. W., & Titus, R. (2020). Consequences of Strategic Performance Measurement Systems: A Meta-Analytic Review. Journal of Management Accounting Research?arrow_forwardThe table below was compiled for a middle school from the 2003 English/Language Arts PACT exam. Grade 6 7 8 Below Basic 60 62 76 Basic 87 134 140 Proficient 87 102 100 Advanced 42 24 21 Partition the likelihood ratio test statistic into 6 independent 1 df components. What conclusions can you draw from these components?arrow_forward
- What is the value of the maximum likelihood estimate, θ, of θ based on these data? Justify your answer. What does the value of θ suggest about the value of θ for this biased die compared with the value of θ associated with a fair, unbiased, die?arrow_forwardShow that L′(θ) = Cθ394(1 −2θ)604(395 −2000θ).arrow_forwarda) Let X and Y be independent random variables both with the same mean µ=0. Define a new random variable W = aX +bY, where a and b are constants. (i) Obtain an expression for E(W).arrow_forward
- The table below shows the estimated effects for a logistic regression model with squamous cell esophageal cancer (Y = 1, yes; Y = 0, no) as the response. Smoking status (S) equals 1 for at least one pack per day and 0 otherwise, alcohol consumption (A) equals the average number of alcohoic drinks consumed per day, and race (R) equals 1 for blacks and 0 for whites. Variable Effect (β) P-value Intercept -7.00 <0.01 Alcohol use 0.10 0.03 Smoking 1.20 <0.01 Race 0.30 0.02 Race × smoking 0.20 0.04 Write-out the prediction equation (i.e., the logistic regression model) when R = 0 and again when R = 1. Find the fitted Y S conditional odds ratio in each case. Next, write-out the logistic regression model when S = 0 and again when S = 1. Find the fitted Y R conditional odds ratio in each case.arrow_forwardThe chi-squared goodness-of-fit test can be used to test if data comes from a specific continuous distribution by binning the data to make it categorical. Using the OpenIntro Statistics county_complete dataset, test the hypothesis that the persons_per_household 2019 values come from a normal distribution with mean and standard deviation equal to that variable's mean and standard deviation. Use signficance level a = 0.01. In your solution you should 1. Formulate the hypotheses 2. Fill in this table Range (-⁰⁰, 2.34] (2.34, 2.81] (2.81, 3.27] (3.27,00) Observed 802 Expected 854.2 The first row has been filled in. That should give you a hint for how to calculate the expected frequencies. Remember that the expected frequencies are calculated under the assumption that the null hypothesis is true. FYI, the bounderies for each range were obtained using JASP's drag-and-drop cut function with 8 levels. Then some of the groups were merged. 3. Check any conditions required by the chi-squared…arrow_forwardSuppose that you want to estimate the mean monthly gross income of all households in your local community. You decide to estimate this population parameter by calling 150 randomly selected residents and asking each individual to report the household’s monthly income. Assume that you use the local phone directory as the frame in selecting the households to be included in your sample. What are some possible sources of error that might arise in your effort to estimate the population mean?arrow_forward
- For the distribution shown, match the letter to the measure of central tendency. A B C C Drag each of the letters into the appropriate measure of central tendency. Mean C Median A Mode Barrow_forwardA physician who has a group of 38 female patients aged 18 to 24 on a special diet wishes to estimate the effect of the diet on total serum cholesterol. For this group, their average serum cholesterol is 188.4 (measured in mg/100mL). Suppose that the total serum cholesterol measurements are normally distributed with standard deviation of 40.7. (a) Find a 95% confidence interval of the mean serum cholesterol of patients on the special diet.arrow_forwardThe accompanying data represent the weights (in grams) of a simple random sample of 10 M&M plain candies. Determine the shape of the distribution of weights of M&Ms by drawing a frequency histogram. Find the mean and median. Which measure of central tendency better describes the weight of a plain M&M? Click the icon to view the candy weight data. Draw a frequency histogram. Choose the correct graph below. ○ A. ○ C. Frequency Weight of Plain M and Ms 0.78 0.84 Frequency OONAG 0.78 B. 0.9 0.96 Weight (grams) Weight of Plain M and Ms 0.84 0.9 0.96 Weight (grams) ○ D. Candy Weights 0.85 0.79 0.85 0.89 0.94 0.86 0.91 0.86 0.87 0.87 - Frequency ☑ Frequency 67200 0.78 → Weight of Plain M and Ms 0.9 0.96 0.84 Weight (grams) Weight of Plain M and Ms 0.78 0.84 Weight (grams) 0.9 0.96 →arrow_forward
MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSON
The Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. Freeman
Introduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman