Probability and Statistics

Your portfolio is invested 30 percent each in A and C, and 40 percent in B. What is the expected return of the portfolio? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) What is the variance of this portfolio? (Do not round intermediate calculations and round your answer to 5 decimal places, e.g., 32.16161.) What is the standard deviation? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.

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EXPERT ANSWER Investment in Stock A =0.30 Investment in Stock A =0.40 Investment in Stock C=0.30 Boom E(Rp)= 0.30(0.34) +0.40( 0.44) +0.30(0.35) = 0.102+ 0.176+ 0.105 =0.3830 or 38.30% Good E(Rp)= 0.30(0.18) +0.40( 0.15) +0.30(0.09) = 0.054+ 0.06+ 0.027 = 0.1410 or 14.10% Poor E(Rp)= 0.30(-0.02) +0.40( -0.05) +0.30(-0.04) = -0.006+ -0.02+ -0.01 = -0.0380 …

Your portfolio is invested 30 percent each in A and C, and 40 percent in B. What is the expected return of the portfolio? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) What is the variance of this portfolio? (Do not round intermediate calculations and round your answer to 5 decimal places, e.g., 32.16161.) What is the standard deviation? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16. Read More »

A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 25. (a) How large must n be if the length of the 95% CI is to be not greater than 50? (b) How large must n be if the length of the 99% CI is to be not greater than 50?

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A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 25. (a) How large must n be if the length of the 95% CI is to be not greater than 50? (b) How large must n be if …

A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 25. (a) How large must n be if the length of the 95% CI is to be not greater than 50? (b) How large must n be if the length of the 99% CI is to be not greater than 50? Read More »

A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 15.

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A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 15. (a) How large must n be if the length of the 95% CI is to be not greater than 30? (b) How large must n be if …

A confidence interval estimate is desired for the gain in a circuit on a semiconductor device. Assume that gain is normally distributed with standard deviation s = 15. Read More »

An article in Medicine and Science in Sports and Exercise [“Maximal Leg-Strength Training Improves Cycling Economy in Previously Untrained Men” (2005, Vol. 37, pp. 131-136)] studied cycling performance before and after eight weeks of leg-strength training. Seven previously untrained males performed leg-strength training three days per week for eight weeks (with four sets of five replications at 85% of one repetition maximum). Peak power during incremental cycling increased to a mean of 315 watts with a standard deviation of 16 watts. Construct a 95% confidence interval for the mean peak power after training.

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A manufacturer is interested in the output voltage of a power supply used in a PC. Output voltage is assumed to be normally distributed with a standard deviation 0.25 volts and the manufacturer wishes to test the hypothesis H0: µ = 5 against H1: µ > 5 volts using n = 8 units.

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A manufacturer is interested in the output voltage of a power supply used in a PC. Output voltage is assumed to be normally distributed with a standard deviation 0.25 volts and the manufacturer wishes to test the hypothesis H0: µ = 5 against H1: µ > 5 volts using n = 8 units. (a) The …

A manufacturer is interested in the output voltage of a power supply used in a PC. Output voltage is assumed to be normally distributed with a standard deviation 0.25 volts and the manufacturer wishes to test the hypothesis H0: µ = 5 against H1: µ > 5 volts using n = 8 units. Read More »

A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and ẋ = 2.78. It is known that σ = 0.9 and that wear is normally distributed.

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A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and ẋ = 2.78. It is known that σ = 0.9 and that wear is normally distributed. Test H0 : μ ≠3 using α = 0.05. …

A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and ẋ = 2.78. It is known that σ = 0.9 and that wear is normally distributed. Read More »

A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and x = 2.78. It is known that σ = 0.9 and that wear is normally distributed.

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A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and x = 2.78. It is known that σ = 0.9 and that wear is …

A manufacturer produces crankshafts for an automobile engine. The crankshafts wear after 100,000 miles (0.0001 inch) is of interest because it is likely to have an impact on warranty claims. A random sample of n = 15 shafts is tested and x = 2.78. It is known that σ = 0.9 and that wear is normally distributed. Read More »

34. For its Music 360 survey, Nielsen Co. asked teenagers how they listened to music in the past 12 months. Nearly two-thirds of U.S. teenagers under the age of 18 say they use Google Inc.’s video-sharing site to listen to music and 35% of the teenagers said they use Pandora Media Inc.’s custom online radio service (The Wall Street Journal, August 14, 2012). Sup- pose 10 teenagers are selected randomly to be interviewed about how they listen to music. Is randomly selecting 10 teenagers and asking whether or not they use Pandora Media What is the probability that none of the 10 teenagers uses Pandora Media Inc.’s online What is the probability that 4 of the 10 teenagers use Pandora Media Inc.’s online What is the probability that at least 2 of the 10 teenagers use Pandora Media Inc.’s a. 2 Inc.’s online service a binomial experiment? radio service? radio service? online radio service? b. c. d.

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