Question 1:

1What is a sample statistic? A sample statistic is a descriptive measure uf a . Give examples. {Select all that apply.) What is a population parameter? A population parameter is a Select an answerv descriptive measure of a Select an answerv Give examples. (Select all that apply.) Op O SA population is uniformily distributed from 15 to 30. If a random sample of size n = 22E is selected, a. What is the mean of the distribution of sample means? a = E b. What is the standard deviation of the distribution of sample means? Round to two decimal places. A manufacturer produces a commodity where the length of the commodity has approximately normal distribution 1with a mean of 13.3 inches and standard deviation of 1.5 inches. If a sample of 45 items are chosen at random, what is the probability the sample's mean length is greater than 12.?r inches? Round answer to four decimal places. ll Notation: X ~ U(a, b) means the random variable X is uniformly distributed from a to b . Suppose that the age of students at George Washington Elementary school is uniformly distributed between 5 and 10 years old. 41 randomly selected children from the school are asked their age. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ U Suppose that 41 children from the school are surveyed. Then the sampling distribution is b. What is the distribution of ? ~ ~ N( c. What is the probability that the average of 41 children will be between 7 and 7.6 years old?The amount of syrup that people put on their pancakes is normally distributed with mean 62 mL and standard deviation 9 mL. Suppose that 17 randomly selected people are observed pouring syrup on their pancakes. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ Ni:',:]) b. What is the distribution of :E? :7: ~ Ni:],:') c. If a single randomly selected individual is observed, find the probability that this person consumes is between 64.6 mL and 66.9 mL. :] d. For the group of 17 pancake eaters, find the probability that the average amount of symp is between as mm 66.9 ml. :] e. For part d], is the assumption that the distribution is normal necessary? 0 N00 Yes The average amount of money spent for lunch per person in the college cafeteria is 56.96 and the standard deviation is $2.46. Suppose that 12 randomly selected lunch patrons are observed. Assume the distribution of money spent is normal, and round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ Nt:|,l:]) b. What is the distribution of 5:? 5: ~ N{|:],|:|) c. For a single randomly selected lunch patron, find the probability that this patron's lunch cost is between 56.9249 and $7.92. d. For the group of 11 patrons, find the probability that the average lunch cost is between 56.9249 and 5192. e. For part d), is the assumption that the distribution is normal necessary? 0 NoO Yes A leading magazine [like Barron's) reported at one time that the average number of weeks an individual is unemployed is R weeks. Assume that the length of unemployment is normally distributed with population mean of 23 weeks and the population standard deviation of 2 weeks. Suppose you would like to select a random sample of 38 unemployed individuals for a followup study. Round the answers of following questions to 4 decimal places. a. What is the distribution of X? X ~ N[:|,l:]) b. What is the distribution of :E? :7: ~ Ni:|,|:]) c. What is the probability that one randomly selected individual found the next job is less than 23 weeks? d. For 38 unemployed individuals, nd the probability that the average time that they found the next job is less than N weeks. e. For part d], is the assumption of normal necessaryiI O YesD No The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with Lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.5 years and a standard deviation of 0.4 years. He then randomly selects records on 13 laptops sold in the past. Round the answers of following questions to 4 decimal places. a. What is the distribution of X? X ~ Ni:],:]} b. What is the distribution of 5-? - ~ MIC],:]) c. 1What is the probability that one randomly selected laptop is replaced more than 4.4 years! |:| d. For 18 Laptops, find the probability that the average replacement time is more than 4.4 year. |:| e. For part d], is the assumption of normal necessary? 0 No0 Yes