in 2004, an environmental research group studied the performance of truss and frame structures subjected to uncertain loads. the load was assumed to have a normal distribution with a mean of 20 pounds. Also, the probability that the load is between 16 and 24 pounds is 0.34. On the basis of this information, find the variance of the load distribution.
Q: A school administrator wants to see if there is a difference in the number of students per class for…
A: Public School district Sample size, n1=26 Sample mean, x¯1=35 Sample sd, s1=2 Beaverton School…
Q: A group of students (large group) took a test in mathematics and the final scores have a mean of 68…
A: Given information: The final scores in a mathematics test has Normal distribution. Considering the…
Q: In a given population for beverage drinkers, an individual's per kg expenditure on tea (T) and their…
A: Given : Tea : mean = 2.95 variance = 0.16 Coffee : mean = 2.12 variance = 0.09 Cov (T , C) = 0.15
Q: The time spent on volunteer activities varies within a group of students. A particular group of…
A: Mean μ=2, standard deviations σ=3 , n=100 P( x̄>2.5)=?
Q: School district (group 1) compared to the Beaverton School district (group 2). Assume the ations are…
A: Given Group 1 n1=26 Xbar1=33 S1=6 Group 2 n2=25 Xbar2=36 S2=2
Q: Assume average grade of Physics 1 was 74 in fall 2019. We estimated the average grade of Physics 1…
A:
Q: Find a 99% confidence interval in the difference of the means. Use technology to find the critical…
A:
Q: A bakery is considering buying one of two gas ovens. The bakery requires that the temperature remain…
A: Hypothesis Testing: It is basically a comparison of the statistical measures of the data with one…
Q: The revenue of a new product is $60 per unit. The production cost is given by a discrete…
A: Given information: The revenue of a new product is $60 per unit. The production cost is given by a…
Q: Compute the mean, variance, and standard deviation of the GMAT scores for the 51 observations.…
A: Given Data : 345 749 427 765 336 777 663 451 787 454 711 544 453 330 718 462 585 658…
Q: Researchers conducted a study to determine if magnets are effective in treating back pain. Subjects…
A: Group 1: Real Magnets n1=22 x1-=4.9 s1=0.96 Group 2 : Fake Magnet n2=21 x2-=5.2 s2=1.4 We have…
Q: Assume thAt scores on a standardized test are known to follow a bell shaped distribution with a mean…
A: L
Q: For a class project, statistics students asked students in their class (30 students) how many hours…
A: Hello! As you have posted more than 3 sub parts, we are answering the first 3 sub-parts. In case…
Q: A data set from a study that examined the effect of a specific diet on blood pressure is below.…
A: Given Information : A data set from a study that examined the effect of a specific diet on blood…
Q: Suppose that the random variable X measures the number of hot dogs purchased in a food court in an…
A: CorX,Y=0.75VX=VY=36W=2X+3Y
Q: Suppose that in a certain year, it was reported that the variance in GMAT scores was 14,650. At a…
A: (a) Determine the value of sample mean, variance and standard deviation Use EXCEL Procedure to…
Q: A researcher wants to test the claim that convicted burglars spend an average of 18.7 months in…
A: It is given that the sample size is 11; the sample mean is 32 and the sample standard deviation is…
Q: The next seven questions refer to the following scenario: A random sample of 16 Porsche drivers…
A: Given that, a random sample of 16 Porsche drivers yielded an average age of 50 years with a variance…
Q: One study claims that the variance in the resting heart rates of smokers is different than the…
A: Sample 1(smokers): n1=9s12=581.4 Sample 2(non-smokers): n2=9s22=103.8 Level of significance, α=0.05…
Q: A parenting magazine reports that the average amount of wireless data used by teenagers each month…
A: State the null and alternative hypotheses for the test. Fill in the blank below. H0: μ=6:…
Q: In a recently conducted survey, workers reported driving an average of 36 miles one way on their…
A: Given Population mean = 36miles Population standard deviation =5
Q: A school administrator wants to see if there is a difference in the number of students per class for…
A: using excel we find critical value
Q: A researcher wishes to test if the variance of scores on a particular exam is the same for college…
A: The given hypothesis is H0:σA2σB2=1 Versus Ha:σA2σB2≠1
Q: In a within groups design, what will happen to the t statistic if the variance of the difference…
A: We have given the following statement about the t - statistics
Q: If 446 rods are sampled at random from the batch, what is the probability that the mean length of…
A: Here we have given information, A batch of steel rods produced at a steel plant have a mean length…
Q: In semiconductor manufacturing, wet chemical etching is often used to remove silicon from the backs…
A: It is assumed that denotes the data for solution 1 and denotes the data for solution 2.The sample…
Q: a. Are the test scores significantly lower for the con- tact sport athletes than for the noncontact…
A: Solution:
Q: A basketball coach believes that the variance of the heights of adult male basketball players is…
A: For the given data Perform F test for the equality of two population variances
in 2004, an environmental research group studied the performance of truss and frame structures subjected to uncertain loads. the load was assumed to have a
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 3 images
- A study shows that running increases the percent resting metabolic rate (RMR) in older women. The average RMR of 25 elderly women runners was 33.1% higher than the average RMR of 25 sedentary elderly women, and the standard deviations were reported to be 10.5% and 10 2%, respectively. Was there a significance increase in RMR of the women runners over the sedentary women? Assume the populations to be approximately normally distributed with equal variances. Use a P-value in the conclusion. Click here to view page 1 of the table of critical values of the t-distribution. Click here to view page 2 of the table of critical values of the t-distribution. Let sample 1 be the women runners and let sample 2 be the sedentary women. State the null and alternative hypotheses. Ho-H, H H₁ H₂One study claims that the variance in the resting heart rates of smokers is different than the variance in the resting heart rates of nonsmokers. A medical student decides to test this claim. The sample variance of resting heart rates, measured in beats per minute, for a random sample of 4 smokers is 126.8. The sample variance for a random sample of 4 nonsmokers is 597.6. Assume that both population distributions are approximately normal and test the study’s claim using a 0.02 level of significance. Does the evidence support the study’s claim? Let smokers be Population 1 and let nonsmokers be Population 2. Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. H0: σ21=σ22: Ha: σ21⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯σ22 Compute the value of the test statistic. Round your answer to four decimal places. Draw a conclusion and interpret the decisionIn a given population for beverage drinkers, an individual's per kg expenditure on tea (7) and their per kg expenditure on coffee (C) have a bivariate normal distribution with covariance 0.15. An individual's per kg expenditure on tea is distributed with mean $2.95 and variance 0.16. An individuals per kg expenditure on coffee is distributed with mean $2.12 and variance 0.09 If each individual in the population drinks 3 kg of tea and 2 kg of coffee, the mean total expenditure on beverages is $13.09 with a variance of 3.60 If T and C have a bivariate normal distribution with covariance zero, the mean total expenditure on beverages is $with a variance of
- The cholesterol levels of adult males are approximately normally distributed with a mean of 224 mg/dL and a variance, o of 495. Some researchers claim that the variance of cholesterol levels of adult males is less than 495. A sample of 17 adult males' blood tests had a mean of 223 mg/dL and a variance of 274. Is there enough evidence to conclude, at the 0.05 level of significance, that the variance of cholesterol levels of adult males is less than 495? 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.) The null hypothesis: H = 495 X The alternative hypothesis: H. < 495 ロ=ロ Degrees of freedom: The type of test statistic: Chi square 16 ロ#ロ OThe next seven questions refer to the following scenario: A random sample of 16 Porsche drivers yielded an average age of 50 years with a variance of 9 years and a random sample of also 16 Ferrari drivers yielded an average of 47 years with a variance of 25 years. Porsche Driver Ferrari Driver n 16 16 mean 50 47 Variance 25 Conduct the following hypothesis test at a=0.05. HO: Mean Age Porsche Drivers Mean Age Ferrari Drivers Assume unequal variance.A researcher randomly sampled 100 graduates of an MBA program and recorded data concerning their starting salaries. Of primary interest to the researcher was the effect of gender on starting salaries. The summary results are given below: Male MBA Graduates: Sample mean = $85500, Sample standard deviation = 10000, Sample size = 50 Female MBA Graduates: Sample mean = $78000, Sample standard deviation = 8000, Sample size = 50 Assuming that the populations are normally distributed and the population variances from both populations are equal, is there evidence that the average starting salary of the male MBA graduates is higher than the average starting salary of the female MBA graduates? Use a 0.05 level of significance. (a) State the null and alternative hypothesis for this problem. (b) What is the value of the pooled-variance tSTAT test statistic for this problem? (c) Using the level of…For a standardized psychology examination, the scores have a mean of 500 and a variance of 9475. It is hypothesized that the variance, o, of scores for psychology majors on this exam is lower than 9475. A random sample of 26 exams completed by psychology majors had a mean of 509 and a variance of 3987. Assuming that scores among psychology majors on this exam are approximately normally distributed, may we conclude, at the 0.01 level of significance, that the hypothesis is correct? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H, :0 H :0 (b) Determine the type of test statistic to use. OSO (Choose one) ▼ (c) Find the value of the test statistic. (Round to three or more decimal places.) ODefine the bias of an arbitrary estimator and show that if an estimator is unbiased then the square error is equal to its variance.A school administrator wants to see if there is a difference in the number of students per class for Portland Public School district (group 1) compared to the Beaverton School district (group 2). Assume the populations are normally distributed with unequal variances. A random sample of 28 Portland classes found a mean of 36 students per class with a standard deviation of 5. A random sample of 27 Beaverton classes found a mean of 35 students per class with a standard deviation of 6. Find a 90% confidence interval in the difference of the means. Use technology to find the critical value using df = 50.6214 and round answers to 4 decimal places.A simple random sample of 100 water meters within a community is monitored to estimate the average daily water consumption per household over a specified dry spell. The mean and variance for this sample are 12 and 1250, respectively. If we assume that there are N= 1000 houscholds within the community, and the maximum and minimum water consumption values per household are 23 and 3 respectively, estimate the true mean of daily water consumption.A company is doing a hypothesis test on the variation in quality from two suppliers. Both distributions are normal, and the populations are independent. Use a = 0.05. A sample of 23 products were selected from Supplier 1 and a standard deviation of quality was found to be 6.659. A sample of 25 products were selected from Supplier 2 and a standard deviation of quality was found to be 2.8432. Test to see if the variance in quality for Supplier 1 is larger than Supplier 2. What are the correct hypotheses? Note this may view better in full screen mode. Select the correct symbols in the order they appear in the problem. Ho: Select an answer Select an answer ✓ H₁: Select an answer Select an answer Based on the hypotheses, compute the following: Round answers to at least 4 decimal places. The test statistic is = The p-value is = The decision is to Select an answer The correct summary would be: [Select an answer quality for Supplier 1 is larger than Supplier 2. that the variance inA basketball coach believes that the variance of the heights of adult male basketball players is different from the variance of heights for the general population of men. The sample variance of heights, measured in inches, for a random sample of 19 basketball players is 14.22. The sample variance for a random sample of 18 other men is 34.49. Assume that both population distributions are approximately normal and test the coach's claim using a 0.10 level of significance. Does the evidence support the coach's claim? Let male basketball players be Population 1 and men in general be Population 2. Step 3 of 3: Draw a conclusion and interpret the decision.SEE MORE QUESTIONSRecommended textbooks for youMATLAB: 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. FreemanMATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th…StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C…StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage LearningElementary Statistics: Picturing the World (7th E…StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman