A researcher conducts a two-year study comparing the number of cavities in a group of 30 randomly selected young children from the community before and after the application of fluoride to test if there is a decrease in the number of cavities. This is an example of a/an: Independent-samples t test or Dependent-samples t test?

A researcher conducts a two-year study comparing the number of cavities in a group of 30 randomly selected young children from the community before and after the application of fluoride to test if there is a decrease in the number of cavities. This is an example of a/an: Independent-samples t test or Dependent-samples t test?

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Three samples of each of three types of PVC pipe of equal wall thickness are tested to failure under three temperature conditions, yielding the results shown below. Research questions: Is mean burst strength affected by temperature and/or by pipe type? Is there a “best” brand of PVC pipe? Burst Strength of PVC Pipes (psi) Temperature PVC1 PVC2 PVC3 Hot (70º C) 247 299 239 277 287 262 283 275 279 Warm (40º C) 325 341 297 322 319 315 296 335 304 Cool (10º C) 358 375 327 366 352 334 338 359 340 Click here for the Excel Data File (a-1) Choose the correct row-effect hypotheses. a. H0: A1 ≠ A2 ≠ A3 ≠ 0 ⇐⇐ Temperature means differ H1: All the Aj are equal to zero ⇐⇐ Temperature means are the same b. H0: A1 = A2 = A3 = 0 ⇐⇐ Temperature means are the same H1: Not all the Aj are equal to zero ⇐⇐ Temperature means differ a b (a-2) Choose the correct column-effect hypotheses. a. H0: B1 ≠ B2 ≠ B3 ≠ 0 ⇐⇐…
QUESTION 1 A magazine article reported that more than 11% of adults buy takeout food daily. A fast-food restaurant owner surveyed 200 customers and found that 32 said that they purchased takeout food daily. At  = 0.05, is there evidence to believe the articles’ claim? QUESTION 2 [5m] The average family size was reported as 3.18. A random sample of families in a particular district resulted the following family sizes: 5 4 5 4 4 3 6 4 3 3 5 6 3 3 2 7 4 5 2 2 2 At  = 0.01, does the average family size in that district differ from the national average?
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Question 1 Select all that apply. Newborn Brain Damage Researchers studied 208 infants whose brains were temporarily deprived of oxygen due to complications at birth. When researchers detected oxygen deprivation, they randomly assigned babies to either usual care or to a whole-body cooling group. The goal was to see whether reducing body temperature for three days after birth increased the rate of survival without brain damage. Which of the following is used in the design of this experiment? Check all that apply. Random assignment Control group Double blinding Question 2 Select one answer. Researchers studied 208 infants whose brains were temporarily deprived of oxygen due to complications at birth. When researchers detected oxygen deprivation, they randomly assigned babies to either usual care or to a whole-body cooling group. The goal was to see whether reducing body temperature for three days after birth increased the rate of survival without brain damage. What…
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QUESTION 10 A retail chain would like to test if a difference exists between the variability of customer satisfaction scores from two locations. The following data represents satisfaction scores from a random sample of customers from these locations on a scale of 1-20. 14 20 18 15 17 16 Location 1 Location 2 12 18 19 17 18 16 20 The test statistic for this hypothesis test would be O A. 1.965 OB. 3.500 OC.3.078 OD.2.431
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The human resources director of a large company recently asked her staff to conduct a study of the airline miles traveled by executives of the company during the most recent calendar year. The analyst assigned to the project randomly sampled 25 male executives and 25 female executives. Of particular interest to the HR director is whether males have greater variability in miles flown than females. The statistics available below were computed from the samples. Based on these data, what should the HR director conclude if an alpha level equal to 0.01 is used? LOADING... Click the icon to view the statistics about the number of miles flown. Males Females Mean Miles 73,262 66,888 St. Deviation Miles 2,568 1,539 Sample Size 25 25 Let sample 1 be males and sample 2 be females. What are the null and alternative hypotheses? A. H0: σ21=σ22 HA: σ21≠σ22 B. H0: σ21≤σ22 HA: σ21>σ22 C. H0: σ21≥σ22 HA:…