4. According to past records, the average project completion time for a specific type of project of a construction company is 32 weeks with a standard deviation of 12 weeks. A random sample of 36 projects of similar type was selected from the records of the company. (a) Which type of distribution will the sample mean project completion time follow and what is the mean and standard deviation of this distribution? (b) What is the probability that the sample mean project completion time will be greater than 30 weeks? (c) After doing some analysis with the sample, the project manager wishes to set a time T (in week) as the deadline for all future similar types of projects. If it is expected that the probability that the sample mean project completion time will not exceed time T is 90%, find the value of T.

4. According to past records, the average project completion time for a specific type of project of a construction company is 32 weeks with a standard deviation of 12 weeks. A random sample of 36 projects of similar type was selected from the records of the company. (a) Which type of distribution will the sample mean project completion time follow and what is the mean and standard deviation of this distribution? (b) What is the probability that the sample mean project completion time will be greater than 30 weeks? (c) After doing some analysis with the sample, the project manager wishes to set a time T (in week) as the deadline for all future similar types of projects. If it is expected that the probability that the sample mean project completion time will not exceed time T is 90%, find the value of T.

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Suppose the average amount of money that people spend on their pets per month is 47 dollars, with a standard deviation of 6 dollars. For a sample of 36 people, final the average amount of money spent on pets that defines the bottom 30% in the distribution.For a sample of 36 people, what is the probability for this sample’s mean to be higher than 50 dollars.
In a research study, conducted by the National Institute of Health, 25 individuals were sampled measuring their triglyceride levels. If the distribution of triglyceride levels for 25 to 55 year old females has a mean of 211 mg/dl and a standard deviation of 46 mg/dl, what is the probability that our sample mean will be above 240?
Suppose the heights of 18-year-old men are approximately normally distributed, with mean 66 inches and standard deviation 5 inches. What is the probability that an 18-year-old man selected at random is between 65 and 67 inches tall? If a random sample of ten 18-year-old men is selected, what is the probability that the mean height x is between 65 and 67 inches?
For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 505 and a standard deviation of 170. The grading process of this year's exam has just begun. The mean score of the 40 exams graded so far is 528. What is the probability that a sample of 40 exams will have a mean score of 528 or more if the exam scores follow the same distribution as in the past? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places. 0 X Ś
For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 510 and a standard deviation of 175. The grading process of this year's exam has just begun. The mean score of the 40 exams graded so far is 530. What is the probability that a sample of 40 exams will have a mean score of 530 or more if the exam scores follow the same distribution as in the past? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places. 0 S
7. Furnace repair bills are normally distributed with a mean of 267 dollars and a standard deviation of 20 dollars. If 74 of these repair bills are randomly selected, find the probability that they have a mean cost between 267 dollars and 269 dollars.
9.An automobile insurer has found that repair claims are Normally distributed with a mean of $530 and a standard deviation of $480. (a) Find the probability that a single claim, chosen at random, will be less than $490. (b) Now suppose that the next 60 claims can be regarded as a random sample from the long-run claims process. Find the probability that the average X¯ of the 60 claims is smaller than $490. (c) If a sample larger than 60 claims is considered, there would be __________ chance of getting a sample with an average smaller then $490. (NOTE: Write ''LESS'', ''MORE'' or ''AN EQUAL''.)
For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 515 and a standard deviation of 170. The grading process of this year's exam has just begun. The mean score of the 35 exams graded so far is 518. What is the probability that a sample of 35 exams will have a mean score of 518 or more if the exam scores follow the same distribution as in the past? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.
For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 515 and a standard deviation of 175. The grading process of this year's exam has just begun. The average score of the 40 exams graded so far is 518. What is the probability that a sample of 40 exams will have a mean score of 518 or more if the exam scores follow the same distribution as in the past? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places. Sub Continue
For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 515 and a standard deviation of 175. The grading process of this year's exam has just begun. The average score of the 35 exams graded so far is 526. What is the probability that a sample of 35 exams will have a mean score of 526 or more if the exam scores follow the same distribution as in the past? Carry your intermediate computations to at least four decimal places: Round your answer to at least three decimal places. Submit Assignment 2021 McGraw Hil LLC. All Rights Reserved. Terms of Use Privacy Center Accessibility US Continue V O 8:19 hp esc 2# 8. 3 4. t 00
Suppose that home prices (in thousands of dollars) in a certain region have a mean of 360 and a standard deviation of 180. A realtor randomly selects a sample of 90 homes in the region. Estimate the probability that the sample mean home price from the realtor's data is greater than 400 (thousand dollars). You must justify your solution, and note any assumptions you are making.
Suppose a college admissions test is normally distributed with a mean of 500 and a standard deviation of 100. If a student scores in the 75th percentile, what is their test score? If the top 10% of test takers are eligible for a scholarship, what is the minimum score needed to qualify for the scholarship? If the test is taken twice by the same student, and the scores are independent, what is the probability that their average score is above 550?