A class survey in a large class for first-year college students asked, "About how many hours do you study during a typical week?" The mean response of the 463 students was x = 15.8 hours. Suppose that we know that the study time follows a Normal distribution with standard deviation o = 8.3 hours in the population of all first-year students at this university. (a) Use the survey result to give a 99% confidence interval for the mean study time of all first-year students. (Round your answers to once decimal place.) 12 X to 14 X hours (b) What condition not yet mentioned must be met for your confidence interval to be valid? O We need to know this sample can be considered an SRS of the population of all first-year students at this university. e We need to know if this sample is normally distributed.

A class survey in a large class for first-year college students asked, "About how many hours do you study during a typical week?" The mean response of the 463 students was x = 15.8 hours. Suppose that we know that the study time follows a Normal distribution with standard deviation o = 8.3 hours in the population of all first-year students at this university. (a) Use the survey result to give a 99% confidence interval for the mean study time of all first-year students. (Round your answers to once decimal place.) 12 X to 14 X hours (b) What condition not yet mentioned must be met for your confidence interval to be valid? O We need to know this sample can be considered an SRS of the population of all first-year students at this university. e We need to know if this sample is normally distributed.

Name: A class survey in a large class for first-year college students asked
Uploaded: 2024-03-20T07:07:12.000Z
Channel: Bartleby
Description: A class survey in a large class for first-year college students asked, "About how many hours do you study during a typical week?" The mean response of the 463 students wasx= 15.8 hours. Suppose that we know that the study time follows a Normal distr

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

#2 A sample of 64 airplanes gave a mean air time (time spent flying) of 49 hours. If the standard deviation is 14.8 hours, construct a 90% confidence interval for u, the true mean air time.
#21)
In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta restaurant, data were collected from 64 randomly selected customers. The sample mean was calculated as $27.75 with a sample standard deviation of $4. We wish to develop a 91% confidence interval for the mean amount spent per customer for dinner at this restaurant. Assume that the standard deviation of the amounts spent by ALL customers is $4.30. What is the variable of interest? ["", "", ""] And is this variable Quantitative or Qualitative? ["", ""] In other words: what is the one piece of info we care about for each individual in the population? Is it a quantitative measurement? Or do we determine if each individual belongs to a certain category (referred to as success) or not (failure)? If it is a quantitative measurement, then the population is filled with numbers. Otherwise, the population is filled with…
The mean change in muscle thickness observed after a 4-week training regimen was 4 mm, and the 95% confidence interval (CI) for mean change was (-0.5, 8.5). Which is the best scientific conclusion for the effectiveness of this regimen ?
According to a recent article about individuals who have credit cards, the mean number of cards per person with credit cards is 4.5. To test this result a random survey of 60 individuals who have credit cards was conducted. The survey only includes the number of credit cards per participant. The results of the survey are attached below. (a) What is the variable of interest in this study? Is it qualitative or quantitative? (b) Do the results of the survey imply that the mean number of cards per individual is less than 4.5? Use the a = 0.05 level of significance. E Click the icon to view the data from the survey. (a) What is the variable of interest in this study? Is it qualitative or quantitative? The variable of interest is number of credit cards.It is a quantitative variable. (b) Do the results of the survey imply that the mean number of cards per individual is less than 4.5? Use the a = 0.05 level of significance. State the null and alternative hypotheses. Họ: H = 4.5 < 4.5 H1: H…
Citrus Rental is a popular car rental agency that has a history of having too few cars available, so that its available cars are overdriven. The mean monthly mileage over the years for Citrus cars has been about 1500 miles per month. Recently, though, Citrus purchased thousands of new cars, and the company claims that the average mileage of its cars is now less than in the past. To test this, a random sample of 11 recent mileages of Citrus cars was taken. The mean of these 11 mileages was 1332 miles per month, and the standard deviation was 232 miles per month. Assume that the population of recent monthly mileages of Citrus cars is normally distributed. At the 0.05 level of significance, can it be concluded that the mean recent monthly mileage, u, of Citrus cars is less than 1500 miles per month? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary,…
A study of the career paths of hotel general managers sent questionnaires to an SRS of 200 hotels belonging to major U.S. hotel chains. There were 99 responses. The average time these 99 general managers had spent with their current company was 11.96 years. (Take it as known that the standard deviation of time with the company for all general managers is 3.8 years.) (a) Find the margin of error for an 85% confidence interval to estimate the mean time a general manager had spent with their current company: years (b) Find the margin of error for a 99% confidence interval to estimate the mean time a general manager had spent with their current company: years
A study of the career paths of hotel general managers sent questionnaires to an SRS of 280 hotels belonging to major U.S. hotel chains. There were 157 responses. The average time these 157 general managers had spent with their current company was 13.28 years. (Take it as known that the standard deviation of time with the company for all general managers is 3 years.) (a) Find the margin of error for an 80% confidence interval to estimate the mean time a general manager had spent with their current company: years (b) Find the margin of error for a 99% confidence interval to estimate the mean time a general manager had spent with their current company: years
A study of the career paths of hotel general managers sent questionnaires to an SRS of 210 hotels belonging to major U.S. hotel chains. There were 88 responses. The average time these 88 general managers had spent with their current company was 11.73 years. (Take it as known that the standard deviation of time with the company for all general managers is 3.6 years.)
I have a question: You are interested in estimating the the mean weight of the local adult population of female white-tailed deer (doe). From past data, you estimate that the standard deviation of all adult female white-tailed deer in this region to be 21 pounds. What sample size would you need to in order to estimate the mean weight of all female white-tailed deer, with a 94% confidence level, to within 4 pounds of the actual weight?
A researcher studying reaction time of drivers states that, "A 95% confidence interval for the mean time it takes for a driver to apply the brakes after seeing the brake lights on a vehicle in front of him is 1.2 to 1.8 seconds." What are the point estimate and margin of error for this interval? Point estimate = 1.5 seconds; margin of error = 0.95 seconds. Point estimate = 1.2 seconds; margin of error = 0.3 seconds. Point estimate = 1.5 seconds; margin of error = 0.6 seconds. Point estimate = 1.5 seconds; margin of error = 0.3 seconds. a O b O d
A psychologist has developed a new test to measure depression. Using a very large group of "normal" individuals, the mean score on this test is found to be p=55 and a population standard of o=12. The scores form a normal distribution. A researcher would like to use this test to evaluate a theory predicting that increased depression is a common part of the aging process. To test the theory, a sample of n=36 elderly people is obtained. The depression test is administered to each person, and the mean score for the sample is 59. Testing the hypothesis using a one-tailed test at 0.05 level of significance, do these data support the theory? You can answer "Yes" or "No". Do the 4-step process to determine the answer. Answer: