A marketing manager wishes to compare the variances in the prices charged for two brands of CD players (assuming the distribution of prices is normal for both brands). The manager conducts a random survey of retail outlets and obtains the following results: Onkyo X1 = 150 JVC X2 = 145 S2 n2 = 24 Mean %3D Standard Deviation = 15 10 S1 = 10 Sample Size n1 Use the information to test H,: of ož with a = conclude? 0.01. What do you

A marketing manager wishes to compare the variances in the prices charged for two brands of CD players (assuming the distribution of prices is normal for both brands). The manager conducts a random survey of retail outlets and obtains the following results: Onkyo X1 = 150 JVC X2 = 145 S2 n2 = 24 Mean %3D Standard Deviation = 15 10 S1 = 10 Sample Size n1 Use the information to test H,: of ož with a = conclude? 0.01. What do you

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

In a test of the effectiveness of garlic for lowering cholesterol, 36 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 0.1 and a standard deviation of 23.2. 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. What are the null and alternative hypotheses? O A. Ho p=0 mg/dL O B. H, p=0mg/dL H, p0 mg/dL OC. Ho H>0 mg/dL O D. H, p=0 mg/dL. H, pz0 mg/dL. H, p<0 mg/dL
The size of the left upper chamber of the heart is one measure of cardiovascular health. When the upper left chamber is enlarged, the risk of heart problems is increased. A paper described a study in which the left atrial size was measured for a large number of children aged 5 to 15 years. Based on these data, the authors concluded that for healthy children, left atrial diameter was approximately normally distributed with a mean of 26.7 mm and a standard deviation of 4.4 mm. (Round your answers to four decimal places.)
A study has been made to compare the nicotine contents of two brands of cigarettes. Ten cigarettes of Brand A had an average nicotine content of 4.3 milligrams with a standard deviation of 0.6 milligram. Eight cigarettes of Brand B had an average nicotine content of 3 milligrams with a standard deviation of 0.4 milligram. Assume that the two sets of data are independent random samples from normal populations with equal variances. Answer the following, and round off your answer to three decimal places. (a) Find a pooled estimate of the population standard deviation. (b) Construct a 95% confidence interval for the difference between the mean nicotine contents of the two brands of cigarettes. (☐☐)
In 2009 Noodles & Company introduced spaghetti and meatballs to its menu. Before putting it on the menu, it performed taste tests to determine the best-tasting spaghetti sauce. In a paired comparison, 35 tasters were asked to rate their satisfaction with two different sauces on a scale of 1 to 10, with 10 being the highest. Assume equal population variances. The mean difference in ratings was d¯d¯ = -0.25944 with a standard deviation of sd = 1.53990. Use α = 0.05. b) Find the test statistic tcalc. (Round your answer to 3 decimal places. A negative value should be indicated by a minus sign.) (c) Find the critical value tcrit for α = .05. (Round your answer to 3 decimal places.) (d) Find the p-value. (Round your answer to 3 decimal places.)
An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 5.5 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 24 engines and the mean pressure was 5.7 pounds/square inch with a variance of 0.49. A level of significance of 0.01 will be used. Assume the population distribution is approximately normal. Make the decision to reject or fail to reject the null hypothesis.
The void volume within a textile fabric affects comfort, flammability, and insulation properties. Permeability of a fabric refers to the accessibility of void space to the flow of a gas or liquid. An article gave summary information on air permeability (cm3/cm2/sec) for a number of different fabric types. Consider the following data on two different types of plain-weave fabric: Fabric Type Sample Size Sample Mean Sample Standard Deviation Cotton 10 51.41 0.75 Triacetate 10 132.15 3.59 Assuming that the porosity distributions for both types of fabric are normal, let's calculate a confidence interval for the difference between true average porosity for the cotton fabric and that for the acetate fabric, using a 95% confidence level. Before the appropriate t critical value can be selected, df must be determined: df = 0.5625 10 + 12.8881 10 2 (0.5625/10)2 9 + (12.8881/10)2 9 = 1.8092 0.1849…
In 2009 Noodles & Company introduced spaghetti and meatballs to its menu. Before putting it on the menu, it performed taste tests to determine the best-tasting spaghetti sauce. In a paired comparison, 66 tasters were asked to rate their satisfaction with two different sauces on a scale of 1 to 10, with 10 being the highest. Assume equal population variances. The mean difference in ratings was d¯d¯ = -0.29798 with a standard deviation of sd = 1.55080. Use α = 0.05. (c) Find the critical value tcrit for α = .05. (Round your answer to 3 decimal places.) (d) Find the p-value. (Round your answer to 3 decimal places.) (e) State your conclusion.
An investigation of the relationship between traffic flow (measured in cars per day) and lead content (measured in micrograms per gram of dry weight) in the bark of trees near the highway yielded the following summary statistics: Sample Mean Sample Standard Deviation Lead Content (micrograms per gram dry weight) y¯=y¯= 680 sysy = 240 Traffic Flow (cars / day) x¯=x¯= 1750 sxsx = 800 The correlation between lead content and traffic flow was found to be r = 0.6 and a scatterplot showed the form to be linear. Since Traffic flow is the X-variable, its mean and standard deviation have been labelled x¯ and sxx¯ and sx. Since Lead content is the Y-variable, its mean and standard deviation have been labelled y¯ and syy¯ and sy . Determine slope and y-intercept of the least squares regression line for using X to predict Y. Group of answer choices Slope y-intercept
A researcher decides to measure anxiety in group of bullies and a group of bystanders using a 23-item, 3 point anxiety scale. Assume scores on the anxiety scales are normally distributed and the variance among the group of bullies and bystanders are the same. A group of 30 bullies scores an average of 21.5 with a sample standard deviation of 10 on the anxiety scale. A group of 27 bystanders scored an average of 25.8 with a sample standard deviation of 8 on the anxiety scale. You do not have any presupposed assumptions whether bullies or bystanders will be more anxious so you formulate the null and alternative hypothesis based on that.
Only need help with finding tcalc.
Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a 0.10 significance level to test for a difference between the measurements from the two arms. What can be concluded? Right arm Left arm 143 179 OA. Ho: H0 H₁: Hd=0 OC. Ho: P = 0 H₁: Hd 0 sufficient evidence to support the claim of a difference in measurements between the two arms.
A 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 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. H0: σ21=σ22: Ha: σ21⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯σ22 Step 2 of 3: Compute the value of the test statistic. Round your answer to four decimal places. Step 3 of 3: Draw a conclusion and interpret the decision.