Exercise Chapter 6 Part 1 [statistic For I.t]

STQS1023 GROUP C & E EXERCISE CHAPTER 6 Part 1 Fill in the blanks by standardizing the normally distributed variable. 1) Dave drives to work each morning at about the same time. His commute time is normally distributed with a mean of 47 minutes and a standard deviation of 8 minutes. The percentage of time that his commute time lies between 23 and 31 minutes is equal to the area under the standard normal curve between ___ and ___. 2) Dave drives to work each morning at about the same time. His commute time is normally distributed with a mean of 38 minutes and a standard deviation of 5 minutes. The percentage of time that his commute time exceeds 44 minutes is equal to the area under the standard normal curve that lies to the ___ of ___. Provide an appropriate response. 3) On the same axes sketch normal distributions with a. μ = 6, σ = 4 b. μ = 6, σ = 2 c. μ = -6, σ = 2 Fill in the blanks by standardizing the normally distributed variable. 4) The amount of time that customers wait in line during peak hours at one bank is normally distributed with a mean of 14 minutes and a standard deviation of 3 minutes. The percentage of time that the waiting time lies between 17 and 19 minutes is equal to the area under the standard normal curve between ___ and ___. Use a table of areas to find the specified area under the standard normal curve. 5) The area that lies between 0 and 3.01 6) The area that lies to the left of 1.13 7) The area that lies to the right of -1.82 Use a table of areas to obtain the shaded area under the standard normal curve.

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10) Use a table of areas for the standard normal curve to find the required z-score. 11)Find the z-score for which the area under the standard normal curve to its left is 0.40 12)Find the z-score having area 0.09 to its left under the standard normal curve. 13) Find z0.45. 14)Determine the two z-scores that divide the area under the standard normal curve into a middle 0.874 area and two outside 0.063 areas.