Cell phones have become an essential part of our everyday lives. We use them for communication, photography, browsing, and banking, among other things. Choosing the right cell phone is important, and is based on several factors, including weight. Suppose the weight of a cell phone is distributed normally with a known population standard deviation of 18 g. A random sample of 15 cell phones was conducted to calculate a sample mean weight of 155.7 g. Construct a 95% confidence interval for the population mean weight, mu. Choose the correct answer below based on constructing this interval (it may be a good idea to write your final interval down, as the next question may relate to this one). Hint: although the sample size is small, you may use the standard normal distribution, as the population standard deviation is known. Hint: we cover this in the video "CI 2020 2" a. the interval is [146.59, 164.81); the critical value used is 1.96 O a) O b) 18 b. the interval is (146.59, 164.81] ; the margin of error is (1.96 * ViS c) c. the interval is (146.59, 164.81]; the margin of error is (1.645 ) 18 d) d. the interval is [137.70, 173.70] ; the margin of error is (1.96 ) O e) e. both a and b are correct

Cell phones have become an essential part of our everyday lives. We use them for communication, photography, browsing, and banking, among other things. Choosing the right cell phone is important, and is based on several factors, including weight. Suppose the weight of a cell phone is distributed normally with a known population standard deviation of 18 g. A random sample of 15 cell phones was conducted to calculate a sample mean weight of 155.7 g. Construct a 95% confidence interval for the population mean weight, mu. Choose the correct answer below based on constructing this interval (it may be a good idea to write your final interval down, as the next question may relate to this one). Hint: although the sample size is small, you may use the standard normal distribution, as the population standard deviation is known. Hint: we cover this in the video "CI 2020 2" a. the interval is [146.59, 164.81); the critical value used is 1.96 O a) O b) 18 b. the interval is (146.59, 164.81] ; the margin of error is (1.96 * ViS c) c. the interval is (146.59, 164.81]; the margin of error is (1.645 ) 18 d) d. the interval is [137.70, 173.70] ; the margin of error is (1.96 ) O e) e. both a and b are correct

ENGR.ECONOMIC ANALYSIS

14th Edition

ISBN:9780190931919

Author:NEWNAN

Publisher:NEWNAN

Chapter1: Making Economics Decisions

Section: Chapter Questions

Problem 1QTC

See similar textbooks

Similar questions

Two teaching methods and their effects on science test scores are being reviewed. A random sample of 11 students, taught in traditional lab sessions, had a mean test score of 76.4 with a standard deviation of 4.1 . A random sample of 18 students, taught using interactive simulation software, had a mean test score of 82.2 with a standard deviation of 5.5 . Do these results support the claim that the mean science test score is lower for students taught in traditional lab sessions than it is for students taught using interactive simulation software? Let μ1 be the mean test score for the students taught in traditional lab sessions and μ2 be the mean test score for students taught using interactive simulation software. Use a significance level of α=0.1 for the test. Assume that the population variances are equal and that the two populations are normally distributed. Step 1 of 4 : State the null and alternative hypotheses for the test.
A major newspaper (that rhymes with Small Street Journal) reported an average household income for its subscribers is $119,155. Assume this estimate of the mean household income is based on a sample of 80 subscribers, and, based on past studies, the population standard deviation is known to be sigma=$30,000. Construct a 95% confidence interval for the population mean. Group of answer choices $60,356 - $177,954 $118,420 - $119,890 $112,447 - $125,863 $112,581 - $125,729
Air Quality Index is a way to measure particle pollution in the air. An index between 0 and 50 is considered good; between 51 and 100 is moderate; more 100 is considered unhealthy for sensitive groups and others. A recent sample data of air quality index values for Pomona in Southern California provided the following data. 50, 52, 59, 56, 58 What are the sample mean, sample variance and the sample standard deviation?
Two teaching methods and their effects on science test scores are being reviewed. A random sample of 5 students, taught in traditional lab sessions, had a mean test score of 76.5 with a standard deviation of 3.3 . A random sample of 11 students, taught using interactive simulation software, had a mean test score of 82.3 with a standard deviation of 4.6 . Do these results support the claim that the mean science test score is lower for students taught in traditional lab sessions than it is for students taught using interactive simulation software? Let μ1 be the mean test score for the students taught in traditional lab sessions and μ2 be the mean test score for students taught using interactive simulation software. Use a significance level of α=0.05 for the test. Assume that the population variances are equal and that the two populations are normally distributed. Step 3 of 4 : Determine the decision rule for rejecting the null hypothesis H0 . Round your answer to three decimal…
High-power experimental engines are being developed by the Stevens Motor Company for use in its new sports coupe. The engineers have calculated the maximum horsepower for the engine to be 830HP . Twenty five engines are randomly selected for horsepower testing. The sample has an average maximum HP of 820 with a standard deviation of 80HP . Assume the population is normally distributed. Step 1 of 2 : Calculate a confidence interval for the average maximum HP for the experimental engine. Use a significance level of α=0.1 . Round your answers to two decimal places.
In testing the population mean,a left-tailed test has a test statistic of z = -2.72.Which is the correct critical value, if we use α=0.005: 2.576 -2.576 1.645 -1.645
Solve all questions
If the level of confidence is lowered from 95% to 90 % , but the allowable error and the standard deviation remain the same, what happens to the required sample size?
All patients admitted to a particular hospital can be released on the same day or kept overnight for observation. In a sample of 2550 patients, 1020 were kept overnight for observation a) What is the point estimate p for the proportion of all patients kept overnight for observation? b) Construct a 99% confidence interval for the proportion of all patients kept overnight for observation.
With 95% confidence, calculate the margin of error to estimate the population mean with a simple random sample of 8 items in a sample standard deviation of 3.5.
A survey on family-friendly housing inventory in Bowling Green is underway to estimate with a 95% confidence interval mean number of 3 bedroom homes for sale. Halfway through their survey, the city reduces the funding available and, consequently, the sample size (total number of houses) must be reduced. In doing so, the margin of error in their analysis will: A. increase, B. stay the same, C. become negative, D. decrease
The higher the confidence level is, 2 points the more precise the confidence interval is True False