12.The life span of an automatic washer X is normally distributed random variable with the mean of3.8 years and standard deviation of 1.2 years.a. Probability that life span of randomly selected washer will be more than 3.5 years isb. The percent of the washers with the life span between 3.5 years and 4.0 years isc. The dealer wants only 1.5% of the washers to fail before the end of guarantee period.Then the length of guarantee period isyears.Show your work in finding probability (percent) in the questions a, b, and answering the question c.

The mean is 3.8 years and the standard deviation is 1.2 years.

Answered: The life span of an automatic washer X…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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The state of California has a mean annual rainfall of 22 inches, whereas the state of New York has a mean annual rainfall of 42 inches. Assume that the standard deviation for both states is 4 inches. A sample of 30 years of rainfall for California and a sample of 46 years of rainfall for New York has been taken. (a) Show the probability distribution of the sample mean annual rainfall for California. inches inches 39.9 40.6 41.3 42 42.7 43.4 44.1 19.9 20.6 21.3 22 22.7 23.4 24.1 inches - 2.1 -1.4 -0.7 0 0.7 1.4 2.1 inches 10 14 18 22 26 30 34 (b) What is the probability that the sample mean is within 1 inch of the population mean for California? (Round your answer to four decimal places.) (c) What is the probability that the sample mean is within 1 inch of the population mean for New York? (Round your answer to four decimal places.)
The state of California has a mean annual rainfall of 19 inches, whereas the state of New York has a mean annual rainfall of 48 inches (Current Results website, October 27, 2012). Assume that the standard deviation for both states is 4 inches. A sample of 30 years of rainfall for California and a sample of 45 years of rainfall for New York has been taken. a. Show the probability distribution of the sample mean annual rainfall for California. This is a normal probability distribution with and (to decimals). b. What is the probability that the sample mean is within inch of the population mean for California? (to decimals) c. What is the probability that the sample mean is within inch of the population mean for New York? (to decimals) d. In which case, part (b) or part (c), is the probability of obtaining a sample mean within inch of the population mean greater? Why? The probability of being within inch is greater because the sample size is .
The number of sales that a car salesperson makes per month is normally distributed with mean 15 and standard deviation 4 . a. Find the probability that a randomly selected car salesperson will sell more than 14 cars this month.b. What is the average number of cars that a group of 25 sales people must sell to be in the 90thpercentile?
Suppose X is a normally distributed random variable with a mean of 9.00. If the probability that X is less than 9.66 is 0.67, then what is the standard deviation of X?
1. Lori just bought a set of 4 tires for her car. The life of a tire is normally distributed with a mean of 45000 miles and a standard deviation of 2000 miles. Find the probability that all 4 tires will last for at least 46000 miles. Assume independence of tires between one another.
Suppose that the distribution of the grades of students in MAPEH performance 1 is roughly normally distributed with a mean of 85 and a standard deviation of 5 a. Between what values do we expect the grades of the middle 68% of the MAPEH students in performance 1 lie? b. Suppose you randomly select 16 MAPEH students, find the probability that the average grades of these students is at least 86. c. A MAPEH student whose grades lies in the upper 1% of the distribution (inclusive of the 1% cutoff) is considered extremely performing in Performance 1. Can you say that Jazzer, a randomly selected student who obtained a grade of 95, is one of those who performed extremely in Performance 1?
About 70% of all female heart transplant patients will survive for at least 3 years. Seventy female heart transplant patients are randomly selected. What is the probability that the sample proportion surviving for at least 3 years will be less than 67%? Assume the sampling distribution of sample proportions is a normal distribution. The mean of the sample proportion is equal to the population proportion and the standard deviation is equal to The probability that the sample proportion surviving for at least 3 years will be less than 67% is
Assume that your aunt wrote 139 letters to her family members in 2019. Let the random variable x represent the number of these letters that she wrote on a given day. Assume also that this scenario has a Poisson distribution. What is the mean number of letters written per day? Round to 3 decimal places. What is the standard deviation? Round to 3 decimal places.
1. Service time for a customer coming through a checkout counter in a retail store is a random variable with the mean of 10.0 minutes and standard deviation of 4.0 minutes. Suppose that the distribution of service time is fairly close to a normal distribution. Suppose there are two counters in a store, n₁ = 41, customers in the first line and m₂ = 51 customers in the second line. Find the probability that the difference between the mean service time for the shorter line and the mean service time for the longer X₂ one ¹2 is more than 0.4 minutes. Assume that the service times for each customer can be regarded as independent random variables.
The average student loan debt for college graduates is $25,050. Suppose that that distribution is normal and that the standard deviation is $13,650. Let X = the student loan debt of a randomly selected college graduate. Round all probabilities to 4 decimal places and all dollar answers to the nearest dollar. b Find the probability that the college graduate has between $23,600 and $33,700 in student loan debt. c. The middle 10% of college graduates' loan debt lies between what two numbers? Low: $ ?High: $ ?
About 79% of all female heart transplant patients will survive for at least 3 years. Seventy female heart transplant patients are randomly selected. What is the probability that the sample proportion surviving for at least 3 years will be less than 75%? Assume the sampling distribution of sample proportions is a normal distribution. The mean of the sample proportion is equal to the population proportion and the standard deviation is equal to pqn.
4. The amount of time between taking a pain reliever and getting relief is normally distributed with a mean of 25 minutes and a standard deviation of 3 minutes. Find the probability that the time between taking the medication and getting relief is as follows. a. At least 30 minutes b. At most 20 minutes 5. All incoming freshmen at a major university are given a mathematics diagnosti exam. The scores are normally distributed with a mean of 120 and a standa deviation of 25. If a student scores less than a certain score, he or she will have undergo an intervention program. Find the cutoff score at which 64% of the stude would have to undergo the intervention program. 2021.04.10 09:47

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