Essentials of Statistics for the Behavioral Sciences
8th Edition
ISBN: 9781133956570
Author: Frederick J Gravetter, Larry B. Wallnau
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 10.4, Problem 1LC
A researcher is using an independent-measures design to evaluate the difference between two treatment conditions with n = 8 in each treatment. The first treatment produces M = 63 with a variance of s2 = 18, and the second treatment has M = 58 with s2 = 14.
a. Use a one-tailed test with
b. Predict how the value for the t statistic would be affected if the two sample variances were increased to s2 = 68 and s2 = 60. Compute the new t to confirm your answer.
c. Predict how the value for the t statistic for the original samples would be affected if each sample had n = 32 scores (instead of n = 8). Compute the new t to confirm your answer.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A researcher obtains t(20) = 2.00 and MD = 9 for a repeated-measures study. If the researcher measures effect size using the percentage of variance accounted for, what value will be obtained for r2?
A snack food manufacturer estimates that the variance of the number of grams of carbohydrates in servings of its tortilla chips is 1.25. A dietician is asked to test this claim and finds that a random sample of 22 servings has a variance of 1.35. At ⍶ = 0.05 is there enough evidence to reject the manufacturer’s claim?
A snack food manufacturer estimates that the variance of the number of grams of carbohydrates in servings of its tortilla chips is
1.141.14.
A dietician is asked to test this claim and finds that a random sample of
2424
servings has a variance of
0.950.95.
At
alpha equals 0.10α=0.10,
is there enough evidence to reject the manufacturer's claim? Assume the population is normally distributed.
Chapter 10 Solutions
Essentials of Statistics for the Behavioral Sciences
Ch. 10.2 - What is the defining characteristic of an...Ch. 10.2 - Prob. 2LCCh. 10.2 - One sample from an independent-measures study has...Ch. 10.2 - One sample from an independent-measures study has...Ch. 10.2 - Prob. 5LCCh. 10.3 - An educational psychologist would like to...Ch. 10.3 - A research report states that there is a...Ch. 10.4 - A researcher is using an independent-measures...Ch. 10.4 - Prob. 2LCCh. 10.4 - When you are using an F-max test to evaluate the...
Ch. 10 - Describe the basic characteristics that define an...Ch. 10 - Describe what is measured by the estimated...Ch. 10 - If other factors are held constant, explain how...Ch. 10 - Describe the homogeneity of variance assumption...Ch. 10 - One sample has SS = 36 and a second sample has SS...Ch. 10 - One sample has SS = 70 and a second sample has SS...Ch. 10 - As noted on page 283, when the two population...Ch. 10 - Two samples are selected from the same population....Ch. 10 - Two separate samples, each with n = 15 individuals...Ch. 10 - Two separate samples, receive different...Ch. 10 - For each of the following, assume that the two...Ch. 10 - For each of the following, calculate the pooled...Ch. 10 - A researcher conducts an independent-measures...Ch. 10 - In a recent study, Piff, Kraus, Ct, Cheng, and...Ch. 10 - Hallam, Price, and Katsarou (2002) investigated...Ch. 10 - It appears that there is some truth to the old...Ch. 10 - Does posting caloric content for menu items affect...Ch. 10 - In 1974, Loftus and Palmer conducted a classic...Ch. 10 - Numerous studies have found that males report...Ch. 10 - Recent research has shown that creative people are...Ch. 10 - When people learn a new task, their performance...Ch. 10 - Recent research has demonstrated that music-based...Ch. 10 - Downs and Abwender (2002) evaluated soccer players...Ch. 10 - Research has shown that people are more likely to...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- To evaluate the effect of a treatment, a sample is ob- tained from a population with a mean of u= 40, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M =44.5 with a variance of s2 = 36. If the sample consists of n = 4 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? b. If the sample consists of n = 16 individuals, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05? c. Comparing your answers for parts a and b, how does the size of the sample influence the outcome of a hypothesis test?arrow_forwardA juice factory buys apple concentrate from two different suppliers. The mean concentration is the same for both suppliers, but it is suspected that the variability of the concentration could be different for the two suppliers. The standard deviation of the concentration in a random sample of n1 = 12 lots produced by Supplier 1 is s1 = 6.4 g / L, and for Supplier 2, n2 = s2 = 4.8 g / L in a random sample of 12 lots. Is there sufficient evidence to conclude that the variance of the two populations is different by calculating the appropriate test statistic? (α = 0.05)arrow_forwardA researcher conducts an independent-measures study comparing two treatments and reports the t statistic as t(25)=2.071 . How many individuals participated in the entire study? Using a two-tailed test with αα=.05 , is there a significant difference between the two treatments? Compute r2 to measure the percentage of variance accounted for by the treatment effect.arrow_forward
- A snack food manufacturer estimates that the variance of the number of grams of carbohydrates in servings of its tortilla chips is 1.34. A dietician is asked to test this claim and finds that a random sample of 16 servings has a variance of 1.22. At α=0.05, is there enough evidence to reject the manufacturer's claim? Assume the population is normally distributed. Complete parts (a) through (e) below.arrow_forwardA researcher conducts an independent- measures research study and obtains t = 2.070 with df = 28. How many individuals participated in the entire research study? Using a two- tailed test with α = .05, is there a significant difference between the two treatment conditions? Compute r2 to measure the percentage of variance accounted for by the treatment effect.arrow_forwardA sample of 12 scores has a variance of s2 = 48. What is the estimated standard error for the samplemeanarrow_forward
- To evaluate the effect of a treatment, a sample is obtained from a population with a mean of µ=20, and the treatment is administered to the individuals in the sample. After the treatment, the sample mean is found to be M=21.3 with a variance of s²=9. a. Assuming that the sample consists of n=16 individuals , use a two-tailed hypothesis test with α=.05 to determine whether the treatment effect is significant and compute both Cohen's d and r² to measure effect size. Are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α=.05? b. Assuming that the sample consists of n=36 individuals, repeat the test and compute both measures of effect size. c. Comparing your answers for parts a and b, how does the size of the sample influence the outcome of a hypothesis test and measures of effect size?arrow_forwardThe NAEP considers that a national average of 283 is an acceptable performance. Using α = .05, run a two-tail t-test for one sample to test Ho: µ=283 for the 2019 scores. Report the t-obt, df, and p-values. Would you reject the null hypothesis that the 2019 scores come from a population with average 283? If this is the case, does it come from a population from larger or smaller average?arrow_forwardA sample of 16 items from population 1 has a sample variance of 5.4 and a sample of 20 items from population 2 has a sample variance of 2.4. Test the following hypotheses at the 0.05 level of significance.arrow_forward
- With standard deviations of s1 = 8.88 and s2 = 30.22, and sample sizes of n1 = 7 and n2 = 8, find the degrees of freedom of a Two Sample Separate Variance t Test. Find the Critical Value if the test is a right-tailed test and the alpha is 0.05.arrow_forwardTwo samples of size 25 and 35 are independently drawn from two normal populations where the unknown population variances are assumed to be equal. The number of degrees of freedom of the equal-variances t test statistic is: A. 58 B. 60 C. 35 D. 59 In testing the null hypothesis ?0:?1−?2=0, if H0, if ?0 is false, the test could lead to: A. either a Type I error or a Type II error B. a Type I error C. a Type II error D. none of the abovearrow_forwardTo evaluate the effect of a treatment, one sample of n=8 is obtained from a population mean: u=40 and the treatment is administered to the individuals in the sample After the treatment, the sample mean is found to be M=35. 2. If the sample variance is S2=73, are the dat sufficient to conclude that the treatment has a significant effect using a two-tailed test with alpha=.05?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
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
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
Introduction to experimental design and analysis of variance (ANOVA); Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=vSFo1MwLoxU;License: Standard YouTube License, CC-BY