standard deviation (variances are equal). Confidence interval: df for t-multiple is (df1 + df2)‚ or (n1 – 1) + (n2 - 1) Pooled estimate of common standard deviation: SE of difference between two sample means ------------------------------------------------- Confidence interval for differences in sample means when variance is not equal. ------------------------------------------------- df for t-multiple is given by complex formula not shown in book when variance is not equal. Use StatTools
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8‚ 6‚ 3‚ 1‚ 12 A) 3 B) 5 C) 6 D) 7 Find the mode for the following data? 5‚ 4‚ 3‚ 4‚ 5‚ 6‚ 5‚ 5‚ 3‚ 4 A) 3 B) 4 C) 5 D) 6 If a set of data has 49 values with a variance of 9.6‚ then the standard deviation is _________. A) 1.4 B) 0.4 C) 0.2 D) 3.1 If a data set has 9 values and a standard deviation 9.4‚ then the variance is ________. A) 88.4 B) 3.1 C) 29.5 D) 28.2 The staff at a small company includes: 4 secretaries‚ 20 technicians‚ 4 engineers‚ 2 executives‚ and 50 factory workers
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amount of money actually spent on the completed work = $6‚783.85 SV: this variance is used to calculate how much a project is over or under budget = -$15‚799.04 CV: this variance is used to determine if a project is ahead or behind schedule = $336.35 EAC: the expected total cost required to finish complete work = $34‚489.68 BAC: this is total cost of the project at completion = $36‚199.69 VAC: variance of total cost of the work and expected cost = $1‚710.01 Turn in this sheet
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over the past year? c. If the inflation rate last year was 4 percent‚ what was your total real rate of return on this investment? (Hint: use the Fisher equation) 3. Using the following returns‚ calculate the arithmetic average returns‚ the variances‚ and the standard deviations for X and Y. 4. You bought one of Great White Shark Repellant Co.’s 8 percent coupon bonds one year ago for $1‚030. These bonds make annual payments and mature six years from now. Suppose you decide to sell your bonds
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Case 8-28. Evaluating a Company’s Budget Procedures. 1. Identify the problems that exist in Ferguson & Sons Manufacturing Company’s budgetary control system and explain how the problems are likely to reduce the effectiveness of the system. The overall company’s strategy is not well defined by executives and communicated to the management. There is no goal other the cost reduction at total company level as well as at departmental level. Managers don’t see connection between expenses‚ revenues
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Chapter 8 Index Models 163 Multiple Choice Questions 1. As diversification increases the total variance of a portfolio approaches ____________. A 0 B 1 C the variance of the market portfolio D infinity E none of the above Answer: C Difficulty: Easy Rationale: As more and more securities are added to the portfolio unsystematic risk decreases and most of the remaining risk is systematic as measured by the variance of the market portfolio. 2. The index model was first suggested by ____________. A Graham
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Test of Hypothesis – Large Sample Test Critical Value (Zx) | Level of Significance (x) | | 1% | 5% | Two tailed test | Z = 2.58 | Z = 1.96 | One tailed test | Z = 2.33 | Z = 1.64 | Q. Z= X- μ σ√n = x- μS.EX The mean height of a random sample of 100 students is 64” and standard deviation is 3”. Test the statement that the mean height of population is 67” at 5% level of significance. Solution: We are given n = 100
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c. X is a zero mean Gaussian random variable with variance σ 2 . 4.100 Let X be the number of successes in n Bernoulli trials where the probability of success is p. Let Y = X/n be the average number of successes per trial. Apply the Chebyshev inequality to the event {|Y − p| > a}. What happens as n → ∞? 4.102 a. Find the characteristic function of the random variable X uniformly distributed over [−b‚ b). b. Find the mean and variance of X by applying the moment theorem. 4.105 modified
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he can consider decreasing the variance of the delivery times. The breakdown of the total delivery time into preparation time‚ waiting time and travel time gives us some ideas for the improvement. MEAN(Prep Time) STD(Prep Time) 15.11 1.105976378 Preparation of the pizzas takes 15.1 minutes on the average with a standard deviation of 1.1 minutes. The small standard deviation compared to the mean implies that the preparation process is pretty standard and variance of the preparation time is not
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closely compared to TT Air (1.6602). • Since to the Standard Deviation for AA Fly is closer‚ the variance for AA Fly (1.557) as compared to TT Air (2.756) shows clearly the dispersion rate of both variables. In conclusion‚ this could mean that TT Air has maximized their usage of aircrafts and is more efficient than AA Fly. [Com: Good work on citing the numbers on mean and standard deviation/variance‚ and comparing the utilisation between AA Fly and TT Air. You may want to comment on the shape
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