CHAPTER 06 #1 OF 3

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Question 2 of 14 -/'I E View Policies Current Attempt in Progress Find the area under the standard normal curve between 2 = l.85 and z = 0. Round your answer to four decimal places. 2; || .0. Question 1 of14 > - f'l EE View Policies Current Attempt in Progress How do the width and height of a normal distribution change when its mean remains the same but its standard deviation decreases? As its standard deviation decreases, the width of a normal distribution curve v and its height V. 0.. Question 3 of 14 > - /1 View Policies Current Attempt in Progress Compute the area under the standard normal curve. Round your answers to four decimal places. (a) The area to the right of z = 1.73 equals (b) The area to the left of z = - 1.4 equals (c) The area between z = 0 and z = 3.19 equalsQuestion 4 of14 View Policies Current Attempt in Progress Find the area under the standard normal curve to the left of z = Round your answer to four decimal places. A: "1.56. 0.. Question 5 of14 -/1 E View Policies Current Attempt in Progress Find the area under the standard normal curve to the right of z = 0.63. Round your answer to four decimal places. A: Question 6 of 14 - /1 E ... View Policies Current Attempt in Progress Determine the following probability for the standard normal distribution. Round your answer to four decimal places. P(-1.88 - [1 View Policies Current Attempt in Progress Determine the following probability for the standard normal distribution. Round your answer to four decimal places. P(0 5 z s 2.09) = Question 8 0H4 -/1 View Policies Current Attempt in Progress Obtain the following probability for the standard normal distribution. Round your answer to four decimal places. P(z > 1.86) = Question 9 of14 - M View Policies Current Attempt in Progress Obtain the following probability for the standard normal distribution. Round your answer to four decimal places. P( 2.47 g z s 1.29) = Question 10 of 14 -/'I View Policies Current Attempt in Progress Obtain the following probability for the standard normal distribution. Enter the exact answer. P(z -/1 E What is the difference between the probabilitydistribution of a discrete random variable and that of a continuous random variable? Select each correct a nswer. C] The probability that a continuous random variable x assumes a value within a certain interval is given by the area under the curve between the two limits of the interval. For a discrete random variable the value is given by the summation of values between those two points. C] The probability distribution of a continuous random variable assigns probabilities to points while that of a discrete random variable assigns probabilities to intervals. C] A continuous random variable has countable values, a discrete random variable has values that are not countable. C] A discrete random variable has countable values, a continuous random variable has values that are not countable. D The probability distribution of a discrete random variable assigns probabilities to points while that of a continuous random variable assigns probabilities to intervals. Question 12 of 14 - f'l EE View Policies Current Attempt in Progress Let x be a continuous random variable. What is the probability that X assumes a single value, such as a? O The probability is a. O The probability that x assumes a single value depends on the probability distribution. 0 The probability is 0. O The probability is 0.5. O The probability is 1. 0.. Question 13 of 14 - /1 ... View Policies Current Attempt in Progress Do the width and/or height of a normal distribution change when its standard deviation remains the same but its mean decreases? The width of a normal distribution curve v and its height when its standard deviation remains the same but its mean decreases.Question 14of14 - /1 E .. . View Policies Current Attempt in Progress Find the z value for x = 18 for a normal distribution with u = 30 and o = 5. Enter the exact answer. Z = iQuestion 3 of 9 - /1 E ... View Policies Current Attempt in Progress Find the area between x = 13 and x = 18 under a normal distribution curve with M = 20 and o = 4. Round your answer to four decimal places.Question4of9 -/'I :: View Policies Current Attempt in Progress Let x denote the time it takes to run a road race. Suppose x is approximately normally distributed with a mean of 190 minutes and a standard deviation of 21 minutes. If one runner is selected at random, what is the probability that this runner will complete this road race in less than 162 minutes? Round your answer to four decimal places. 0.. Question 5 of9 - / 1 E View Policies Current Attempt in Progress Letx denote the time taken to run a road race. Suppose x is approximately normally distributed with a mean of 190 minutes and a standard deviation of 21 minutes. If one runner is selected at random, what is the probability that this runner will complete this road race in 220 to 243 minutes? Round your answer to four decimal places. I \"'5'. A LIMA 0.. Question 6 of9 View Policies Current Attempt in Progress Tommy Wait, a minor league baseball pitcher, is notorious for taking an excessive amount of time between pitches. In fact, his times between pitches are normally distributed with a mean of 31 seconds and a standard deviation of 2.8 seconds. What percentage of his times between pitches are longer than 34 seconds? Round your answer to two decimal places. % I a _\\. mu... .0. Question 7 01'9 View Policies Current Attempt in Progress A construction zone on a highway has a posted speed limit of 40 miles per hour. The speeds of vehicles passing through this construction zone are normally distributed with a mean of 37.48 miles per hour and a standard deviation of 4 miles per hour. Find the percentage of vehicles passing through this construction zone that are exceeding the posted speed limit. Round your answer to two decimal places. The percentage is %. Question 8 of9 _ [1 1: View Policies Current Attempt in Progress The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. The expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $45.45. If the management decides to give free gifts to all those customers who spend more than $120 at this supermarket during a visit, what percentage of the customers are expected to get free gifts? Round your answer to two decimal places. % of the customers are expected to get free gifts. .0. Question 9 of 9 -/'I s: View Policies Current Attempt in Progress Determine the value ofzso that the area under the standard normal curve (a) in the right tail is 0.0309. Round the answer to two decimal places. 2 = (b) in the left tail is 0.0517. Round the answer to two decimal places. 2: .0. Question 2 of 6 - /1 . .. Use a table, calculator, or computer to find the specified area under a standard normal curve. Round your answers to 4 decimal places. a) More than a z-score of 2.48; area = b) More than a z-score of 1.7; area = c) More than a z-score of -0.41; area = d) More than a z-score of 00; area = iQuestion 3 of6 _ /1 :2 Determine the value ofzso that the area under the standard normal curve. a. In the right tail is 0.0400. Round your answer to two decimal places. b. In the left tail is 0.0250. Round your answer to two decimal places. c. In the left tail is 0.0035. Omd your answer to two decimal places. Round your answer to two decimal places. d. In the right tail is 0.0470. Round your answer to two decimal places. .0. Question4of6 -/'I s: View Policies Current Attempt in Progress Fast Auto Service provides oil and lube service for cars. It is known that the mean time taken for oil and lube service at this garage is 15 minutes per car and the standard deviation is 2.4 minutes. The management wants to promote the business by guaranteeing a maximum waiting time for its customers. If a customer's car is not serviced within that period, the customer will receive a 50% discount on the charges. The company wants to limit this discount to at most 4% of the customers. What should the maximum guaranteed waiting time be? Assume that the times taken for oil and lube service for all cars have a normal distribution. Round your answer to the nearest minute. The maximum guaranteed waiting time should be approximately minutes. Question 5 of6 _ [1 l: 0.. View Policies Current Attempt in Progress According to the records of an electric company serving the Boston area, the mean electricity consumption during winter for all households is 1650 kilowatt- hours per month. Assume that the monthly electricity consumption during winter by all households in this area have a normal distribution with a mean of 1650 kilowatt-hou rs and a standard deviation of 320 kilowatt-hours.The company sent a notice to Bill Johnson informing him that about 90% of the households use less electricity per month than he does. What is Bill Johnson's monthly electricity consumption? Round your answer to the nearest integer. Bill Johnson's monthly electricity consumption is approximately kWh. Question 6 of 6