13. A random sample has been taken from a normal distribution and the following confidence intervals are constructed using the same data: (38.02,61.98) and (39.95, 60.05) a) What is the value of the sample mean? b) One of these intervals is a 95% CI and the other is a 90% CI. Which one is the 95% and why?

13. A random sample has been taken from a normal distribution and the following confidence intervals are constructed using the same data: (38.02,61.98) and (39.95, 60.05) a) What is the value of the sample mean? b) One of these intervals is a 95% CI and the other is a 90% CI. Which one is the 95% and why?

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...

See similar textbooks

Similar questions

Professor Nord stated that the mean score on the final exam from all the years he has been teaching is a 79%. Colby was in his most recent class, and his class’s mean score on the final exam was 82%. Colby decided to run a hypothesis test to determine if the mean score of his class was significantly greater than the mean score of the population. α = .01. What is the mean score of the population? What is the mean score of the sample? Is this test one-tailed or two-tailed? Why?
3a) The mean IQ of 200 patients in a psychiatric hospital is 91, with a variance of 16, and the distribution is highly negatively skewed. Between what two IQ scores would we expect to find at least 160 of the patients falling? b) If the distribution was mound-shaped and symmetrical, with the same mean and standard deviation as in part A, approximately how many patients would have IQ scores at or below the 5th percentile or above a score of 97? Answers: a) 82 to 100 b) 28.5 or 29
A student was analyzing a data set that was Normally distributed with a mean of . She calculated the z-score of a score z in the data set and looked up this value on a z-table (the same z-tables we have been using in class). The table gave a value of 0.4918 in this instance. Which of the following statements is true. O Any score in this data set has a 49.18% chance of being between 2 and z. O The score has a probability of 49.18. O The standard deviation of this data set is 0.4918 O The score x is 0.4918 standard deviations away from the mean.
A study is conducted to compare the performance of students with more than one personal electronic gadget and those with only one. A number of them were taken as subjects for the study. The mean grades of these students and the standard deviations are shown below: For one gadget: The mean is 83, standard deviation is 12, and sample size is 7. For more than one gadget: The mean is 79, standard deviation is 13, and sample size is 5. Is it possible to conclude that there is no significant difference in the mean grades of the two types of students at a 95% confidence interval? Note: This is a two-tailed test. Also take note that this is finding the difference between two population means.
The weekly expenditure on groceries of a random sample of 100 family households was recorded. It was estimated that the mean expenditure was approximately $240. With rising interest rates and petrol prices, it was anticipated that grocery expenditure might decrease. Which hypothesis test would you use to test this claim? 1.One tailed, one sample t-test 2.Two tailed, one sample t-test 3.One tailed, z-test 4.One-tailed Paired Samples t-test 5.Chi Square
Q4. Identify the incorrect statement below: The estimator, X from a random sample of X A. Is the mean of the population of X. B. Is an unbiased estimator of the population mean. C. Has an expected value equal to the mean of X. D. Is a random variable with a variance smaller than the variance of X. O A. A ОВ. В С. С O D. D
I. There are two samples with means 15 and 18. Both of those samples consist of 24 observations. Sample standard deviations are equal to 4 in both cases. If you want to test whether the difference between the mean in the first and the mean in the second population is equal to 0, what is your decision at the .01 level?
14.
Which type of confidence interval should you use in this situation? A sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. The distribution is approximately normally distributed. Find the 90% confidence interval for the average days worked of all payroll departments. Question 2 options: 1) a confidence interval for the mean using a table value from the standard normal distribution. 2) a confidence interval for the mean using a table value from the t distribution. 3) a confidence interval for a proportion using a table value from the standard normal distribution. 4) a confidence interval for proportion using a table value from the t distribution. 5) none of the above.
9 The standard error of the mean is, a 0.881 b 0.735 c 0.612 d 0.510
No written by hand solution
answer d)