Problem 3A team of mechanical engineering students is analyzing tensile strength of bars used to build a modeltruss bridge. An instructor tells the students that tensile strength is approximately normally distributedwith variance o² = 500 N². A random sample of 25 bars has a mean tensile strength of x = 1025 N.a) Construct a 99% two-sided Cl on mean tensile strength.b) Compare the width of the 99% CI with the width of the 95% CI: that is, evaluate and report thewidth of 99% CIratiowidth of 95% CI

The given data is as follows:Population variance, Sample size, Sample mean,

Answered: Problem 3 A team of mechanical…

Linear Algebra: A Modern Introduction

4th Edition

ISBN:9781285463247

Author:David Poole

Publisher:David Poole

Chapter7: Distance And Approximation

Section7.3: Least Squares Approximation

Problem 31EQ

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Please show me your solutions and interpretations. Show the completehypothesis-testing procedure.A manufacturing company produces bearings. One line of bearings is specified to be 1.64 centimeters (cm) in diameter. A major customer requires that the variance of the bearings be no more than 0.001 cm2. The producer is required to test the bearings before they are shipped, and so the diameters of 16 bearings are measured with a precise instrument, resulting in the following values:1.69 1.62 1.63 1.70 1.66 1.63 1.65 1.71 1.64 1.69 1.57 1.64 1.59 1.66 1.63 1.65Assume bearing diameters are normally distributed. Use the data and α = 0.025 to test the data to determine whether the population of these bearings is to be rejected because of too high variance.
A professor obtains SAT scores and freshman grade point averages (GPAs) for a group of n = 15 college students. The SAT scores have a mean of M = 580 with SS = 22,400, and the GPAs have a mean of 3.10 with SS = 1.26, and SP = 84. A) Find the regression equation for predicting GPA from SAT scores. B) What percentage of the variance in GPAs is accounted for by the regression equation (i.e., compute the correlation, r, then find r2)? C) Does the regression equation account for a significant portion of the variance in GPA? Use a = .05 to evaluate the F-ratio.
Two different formulas of an oxygenated motor fuel are being tested to study their road octane numbers. The variance of road octane number for formula 1 is o? 1.5, and for formula 2 it is o, = 1.2. Two random samples of size n1 15and n2 20 are tested, and the mean octane numbers observed are x 89.5 fluid ounces and X2 93.1 fluid ounces. Assume normality. (a) Test the hypotheses Ho : µ1 = H2 versus Hị :µ1 < µz using a = 0.05. Round your answer to three decimal places (e.g. 98.765). Zo = Но- (b) Calculate a 95% two-sided confidence interval on the mean difference road octane number, x1 – X2. Round your answer to three decimal places (e.g. 98.765). < H1 - H2 < (c) What sample size would be required in each population if you wanted to be 95% confident that the error in estimating the difference in mean road octane number is less than 1? ni = n2 = i . Round your answer up to the nearest integer.
Unfortunately, arsenic occurs naturally in some ground water.t A mean arsenic level of u = 8.0 parts per billion (ppb) is considered safe for agricultural use. A well in Texas is used to water cotton crops. This well is tested on a regular basis for arsenic. A random sample of 36 tests gave a sample mean of x = 7.1 ppb arsenic, with s = 2.2 ppb. Does this information indicate that the mean level of arsenic in this well is less than 8 ppb? Use a = 0.01. A USE SALT (a) What is the level of significance? State the null and alternate hypotheses. O Ho: H= 8 ppb; H,: H > 8 ppb O Ho: H 8 ppb; H: H = 8 ppb (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. O The standard normal, since the sample size is large and a is unknown. O The Student's t, since the sample size is large and a is known. O The standard normal, since the sample size is large and a is known. O The Student's t, since the sample size is large and a is unknown. What is…
Unfortunately, arsenic occurs naturally in some ground water.t A mean arsenic level of u = 8.0 parts per billion (ppb) is considered safe for agricultural use. A well in Texas is used to water cotton crops. This well is tested on a regular basis for arsenic. A random sample of 36 tests gave a sample mean of x = 7.1 ppb arsenic, with s = 2.2 ppb. Does this information indicate that the mean level of arsenic in this well is less than 8 ppb? Use a = 0.01. A USE SALT (a) What is the level of significance? State the null and alternate hypotheses. O Họ: u = 8 ppb; H,: u > 8 ppb O Ho: H 8 ppb; H,: u = 8 ppb (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. The standard normal, since the sample size is large and a is unknown. O The Student's t, since the sample size is large and a is known. O The standard normal, since the sample size is large and a is known. The Student's t, since the sample size is large and a is unknown. What is the…
Two different formulas of an oxygenated motor fuel are being tested to study their road octane numbers. The variance of road octane number for formula 1 is o? = 1.5, and for formula 2 it is o, the mean octane numbers observed are = 89.5 fluid ounces and I2 = 93.1 fluid ounces. Assume normality. = 1.2. Two random samples of size n1 = 15and n2 = 20 are tested, and (a) Test the hypotheses Ho : H1 H2 versus H1 : µ1 < µ2 using a = 0.05. Round your answer to three decimal places (e.g. 98.765). %| Zo v Ho. (b) Calculate a 95% two-sided confidence interval on the mean difference road octane number, x1 – X2. Round your answer to three decimal places (e.g. 98.765).
Unfortunately, arsenic occurs naturally in some ground water.t A mean arsenic level of u = 8.0 parts per billion (ppb) is considered safe for agricultural use. A well in Texas is used to water cotton crops. This well is tested on a regular basis for arsenic. A random sample of 36 tests gave a sample mean of x = 6.7 ppb arsenic, with s = 3.0 ppb. Does this information indicate that the mean level of arsenic in this well is less than 8 ppb? Use a = 0.01. n USE SALT (a) What is the level of significance? State the null and alternate hypotheses. O Ho: H = 8 ppb; H,: u > 8 ppb O Ho: H = 8 ppb; H,: H + 8 ppb O Ho: H 8 ppb; H,: u = 8 ppb O Ho: H = 8 ppb; H,: µ 0.100 O 0.050 < P-value < 0.100 O 0.010 < P-value < 0.050 O 0.005 < P-value < 0.010 P-value < 0.005 Sketch the sampling distribution and show the area corresponding to the P-value. MacBook Pro esc
Snow avalanches can be a real problem for travelers in the western United States and Canada. A very common type of avalanche is called the slab avalanche. These have been studied extensively by David McClung, a professor of civil engineering at the University of British Columbia. Suppose slab avalanches studied in a region of Canada had an average thickness of u = 67 cm. The ski patrol at Vail, Colorado, is studying slab avalanches in its region. A random sample of avalanches in spring gave the following thicknesses (in cm). 59 51 76 38 65 54 49 62 68 55 64 67 63 74 65 79 (i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.) X= cm S= cm (ii) Assume the slab thickness has an approximately normal distribution. Use a 1% level of significance to test the claim that the mean slab thickness in the Vail region is different from that in the region of Canada. (a) What is the level of significance? State the null and…
Snow avalanches can be a real problem for travelers in the western United States and Canada. A very common type of avalanche is called the slab avalanche. These have been studied extensively by David McClung, a professor of civil engineering at the University of British Columbia. Suppose slab avalanches studied in a region of Canada had an average thickness of μ = 68 cm. The ski patrol at Vail, Colorado, is studying slab avalanches in its region. A random sample of avalanches in spring gave the following thicknesses (in cm). 59 51 76 38 65 54 49 62 68 55 64 67 63 74 65 79 (i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.) x = cm s = cm (ii) Assume the slab thickness has an approximately normal distribution. Use a 1% level of significance to test the claim that the mean slab thickness in the Vail region is different from that in the region of Canada. (a) What is the level of significance?

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