MATLAB: An Introduction with Applications
6th Edition
ISBN: 9781119256830
Author: Amos Gilat
Publisher: John Wiley & Sons Inc
expand_more
expand_more
format_list_bulleted
Related questions
Topic Video
Question
Medical researchers interested in determining the relative effectiveness of two different drug treatments on people with a chronic mental illness established two independent test groups. The first group consisted of
10
people with the illness, and the second group consisted of
14
people with the illness. The first group received treatment 1 and had a mean time until remission of
185
days, with a standard deviation of
5
days. The second group received treatment 2 and had a mean time until remission of
179
days, with a standard deviation of
8
days. Assume that the populations of times until remission for each of the two treatments are
0.05
level of significance, that the mean number of days before remission after treatment 1,
μ1
, is greater than the mean number of days before remission after treatment 2,
μ2
?
Perform a one-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.)
|
|
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 4 steps with 4 images
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
- In a test of the effectiveness of garlic for lowering cholesterol, 49 subjects were treated with raw garlic. Cholesterol levels were measured before and after the treatment. The changes (before minus after) in their levels of LDL cholesterol (in mg/dL) have a mean of 0.8 and a standard deviation of 15.5. Use a 0.01 significance level to test the claim that with garlic treatment, the mean change in LDL cholesterol is greater than 0. What do the results suggest about the effectiveness of the garlic treatment? Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim.arrow_forwardLocation is known to affect the number, of a particular item, sold by an auto parts facility. Two different locations, A and B, are selected on an experimental basis. Location A was observed for 13 days and location B was observed for 18 days. The number of the particular items sold per day was recorded for each location. On average, location A sold 39 of these items with a sample standard deviation of 8 and location B sold 55 of these items with a sample standard deviation of 2. Select a 90% confidence interval for the difference in the true means of items sold at location A and B. a) [-17.95, -14.05] b) [-19.85, -12.15] c) [35.78, 42.22] d) [90.78, 97.22] e) [51.78, 58.22] f) None of the abovearrow_forwardAn educator has developed a program to improve math scores on the Texas STAAR test. The average STAAR Mathematics test for the third graders in the district was a mean= 1472. A sample of n= 30 third graders took the new math training prgram before taking the STAAR Math test. The average score for the students was M= 1497. with a standard deviation of s= 145 (note, this is standard deviation, not variance). Was there a significant change in test scores ( use stard devistion of 0.05, two tail test). What conclusion can be made from these data?arrow_forward
- In a test of the effectiveness of garlic for lowering cholesterol, 49 subjects were treated with raw garlic. Cholesterol levels were measured before and after the treatment. The changes (before minus after) in their levels of LDL cholesterol (in mg/dL) have a mean of 0.3 and a standard deviation of 1.71. Use a 0.01 significance level to test the claim that with garlic treatment, the mean change in LDL cholesterol is greater than 0. What do the results suggest about the effectiveness of the garlic treatment? Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim. sample mean x= mg/dL. (Type an integer or a decimal. Do not round.) t= (Round to two decimal places as needed.) P-value= (Round to three decimal places as needed.)arrow_forwardFor a new study conducted by a fitness magazine, 250 females were randomly selected. For each, the mean daily calorie consumption was calculated for a September-February period. A second sample of 210 females was chosen independently of the first. For each of them, the mean daily calorie consumption was calculated for a March-August period. During the September-February period, participants consumed a mean of 2384.3 calories daily with a standard deviation of 192. During the March-August period, participants consumed a mean of 2415.7 calories daily with a standard deviation of 212.5. The population standard deviations of daily calories consumed for females in the two periods can be estimated using the sample standard deviations, as the samples that were used to compute them were quite large. Construct a 95% confidence interval for µ, -H,, the difference between the mean daily calorie consumption u, of females in September-February and the mean daily calorie consumption µ, of females in…arrow_forwardResearchers conducted an experiment to test the effects of alcohol. Errors were recorded in a test of visual and motor skills for a treatment group of 22 people who drank ethanol and another group of 22 people given a placebo. The errors for the treatment group have a standard deviation of 2.10, and the errors for the placebo group have a standard deviation of 0.83. Use a 0.05 significance level to test the claim that the treatment group has errors that vary significantly more than the errors of the placebo group. Assume that the two populations are normally distributed. What are the null and alternative hypotheses? OA. Ho: 002 OC. Ho: 0²=0 H₁:00 OB. Ho: 0²=0 H₁: 0>0 OD. Ho: 6²=0 H₁:arrow_forwardThe stimulant Ritalin has been shown to increase attention span and improve academic performance in children with ADHD (Evans, Pelham, Smith, et al., 2001). To demonstrate the effectiveness of the drug, a researcher selects a sample of n = 25 children diagnosed with the disorder and measures each child’s attention span before and after taking the drug. The data show an average increase of attention span of MD = 6.8 minutes with a standard deviation of s = 5.5. Is this result sufficient to conclude that Ritalin significantly increases attention span? Use a one-tailed test with α = .01. Compute and interpret r2.arrow_forwardResearchers conducted an experiment to test the effects of alcohol. Errors were recorded in a test of visual and motor skills for a treatment group of 22 people who drank ethanol and another group of 22 people given a placebo. The errors for the treatment group have a standard deviation of 2.30, and the errors for the placebo group have a standard deviation of 0.74. Use a 0.05 significance level to test the claim that the treatment group has errors that vary significantly more than the errors of the placebo group. Assume that the two populations are normally distributed. => Identify the test statistic. (Round to two decimal places as needed.) Use technology to identify the P-value. (Round to three decimal places as needed.) What is the conclusion for this hypothesis test? reject/fail to reject?arrow_forwardFor a new study conducted by a fitness magazine, 270 females were randomly selected. For each, the mean daily calorie consumption was calculated for a September-February period. A second sample of 285 females was chosen independently of the first. For each of them, the mean daily calorie consumption was calculated for a March-August period. During the September-February period, participants consumed a mean of 2385.9 calories daily with a standard deviation of 170. During the March-August period, participants consumed a mean of 2414.1 calories daily with a standard deviation of 230. The population standard deviations of daily calories consumed for females in the two periods can be estimated using the sample standard deviations, as the samples that were used to compute them were quite large. Construct a 95% confidence interval for μ₁-₂, the difference between the mean daily calorie consumption μ₁ of females in September-February and the mean daily calorie consumption μ₂ of females in…arrow_forwardLocation is known to affect the number, of a particular item, sold by HEB Pantry. Two different locations, A and B, are selected on an experimental basis. Location A was observed for 18 days and location B was observed for 18 days. The number of the particular items sold per day was recorded for each location. On average, location A sold 39 of these items with a sample standard deviation of 9 and location B sold 55 of these items with a sample standard deviation of 6. Does the data provide sufficient evidence to conclude that the true mean number of sales at location A exceeds the true mean number of sales at location B at the 0.01 level of significance? Select the [Alternative Hypothesis, Value of the Test Statistic]. a) [μ1 − μ2 ≠ 0, t = −6.276] b) [μ1 − μ2 = 0, -6.277] c) [μ1 − μ2 ≠ 0, -0.6277] d) [μ1 − μ2 > 0, t = −6.276] e) [μ1 − μ2 < 0, t = −6.276] f) None of the abovearrow_forwardThe amount of time it takes students to travel to school can vary greatly depending on how far a student lives from the school and what mode of transportation they take to school. A student claims that the average travel time to school for his large district is 20 minutes. To further investigate this claim, he selects a random sample of 50 students from the school and finds that their mean travel time is 22.4 minutes with a standard deviation of 5.9 minutes. He would like to conduct a significance test to determine if there is convincing evidence that the true mean travel time for all students who attend this school is greater than 20 minutes. What are the appropriate hypotheses? A) H0: μ = 20 versus Ha: μ < 20, where μ = the true mean travel time for all students who attend this school B) H0: μ = 20 versus Ha: μ > 20, where μ = the true mean travel time for all students who attend this school C) H0: μ = 20 versus Ha: μ < 20, where μ = the mean travel time for the 50…arrow_forwardIn a test of the effectiveness of garlic for lowering cholesterol, 36subjects were treated with raw garlic. Cholesterol levels were measured before and after the treatment. The changes (before minus after) in their levels of LDL cholesterol (in mg/dL) have a mean of 0.9and a standard deviation of 2.28. Use a 0.05 significance level to test the claim that with garlic treatment, the mean change in LDL cholesterol is greater than 0.What do the results suggest about the effectiveness of the garlic treatment? Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim. a) What are the null and alternative hypotheses? b) Determine the test statistic. c) Determine the P-value. d) (reject/do not reject). There is (sufficient/not sufficient) evidence to conclude that the mean of the population of changes are (=, not, >, <) to 0.arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_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