You would like to construct a 95% confidence interval to estimate the population mean time it takes drivers to react following the application ofbrakes by the driver in front of them. You take a random sample of reaction time measurements and compute their mean to be 1.5 seconds andtheir standard deviation to be 0.4 seconds.(a) What is the best point estimate, based on the sample, to use for the population mean?×(b) For each of the following sampling scenarios, determine which distribution should be used to calculate thecritical value for the 95% confidence interval for the population mean.(In the table, Z refers to a standard normal distribution, and t refers to a t distribution.)secondsSampling scenarioCould useZ tUncleareither Z or tThe sample has size 110, and it is from a non-normallydistributed population with a known standard deviationof 0.45.The sample has size 18, and it is from a normallydistributed population with an unknown standarddeviation.ооооооThe sample has size 20, and it is from a populationwith a distribution about which we know very little.оооооXG

The best point estimate for the population mean is the sample mean. In this case, the sample mean is…

Answered: You would like to construct a 95%…

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

You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 35 bacteria reveals a sample mean of ¯x=76x¯=76 hours. The population standard deviation is known to be 5.6 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.4 hours at a 90% level of confidence. How many more bacteria should you sample to achieve a 0.4 hour margin of error? n = bacteria
There are several sections of Statistics; some in the morning and some in the afternoon. We randomly select n1 40 from the morning section and 44 from the afternoon section. The averages n2 of their scores are X1 76.3 for the morning section and X, = 71.9 for the afternoon section. The known standard deviations of their scores are 01 12.05 for the morning section and 02 13.06 for the afternoon section. Test the claim that the average for all students in the morning and afternoon section is the same. Use a a = 0.05 significance level. a. What is the negative critical region? Give your answer to two decimal places. z c. What is the test statistic? Give your answer to two decimal places. z = d. Do we reject or fail to reject the null hypothesis? OReject Ho OFail to reject Họ
A new screening test for Lyme disease is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. Five hundred people are screened at a clinic during the first year the new test is implemented. Assume the true prevalence of Lyme disease among clinic attendees is 10%. Calculate the predictive value of a positive test.
A new Economic / Social Conservatism Scale has scores between 0 and 30 (0 being extreme liberal, 30 being extreme conservative). The mean score is 21 and standard deviation of scores is 5. You want to convert the original scale (call it X) to a new scale (call it Y) that has scores between 0 and 100. What is the correlation of X and Y?
Suppose you are working with a data set that is normally distributed, with a mean of 250 and a standard deviation of 46. Determine the value of x from the following information. (a) 70% of the values are greater than x. (b) x is less than 16% of the values. (c) 22% of the values are less than x. (d) x is greater than 55% of the values.
Withdrawal symptoms may occur when a person using a painkiller suddenly stops using it. For a special type of painkiller, withdrawal symptoms occur in 4% of the cases. Consider a random sample of 2400 people who have stopped using the painkiller. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of p, where p is the proportion of people in the sample who experience withdrawal symptoms. (b) Find the standard deviation of (c) Compute an approximation for P(p <0.05), which is the probability that fewer than 5% of those sampled experience withdrawal symptoms. Round your answer to four decimal places.
There are many situations in which we want to compare means from populations having standard deviations that are equal. This method applies even if the standard deviations are known to be only approximately equal. Consider a report regarding average incidence of fox rabies in two regions. For region I, n1 = 16, x1 ≈ 4.73, and s1 = 2.84 and for region II, n2 = 15, x2 ≈ 3.93, and s2 = 2.45. The two sample standard deviations are sufficiently close that we can assume ?1 = ?2. Use the method of pooled standard deviation to consider the report, testing if there is a difference in population mean average incidence of rabies at the 5% level of significance. (Round your answer to three decimal places.) t =
A standardized test is given to a sixth-grade class. Historically the mean score has been 151 with a standard deviation of 21. The superintendent believes that the standard deviation of performance may have recently decreased. She randomly sampled 23 students and found a mean of 161 with a standard deviation of 18.2898. Is there evidence that the standard deviation has decreased at the α=0.05 level? Step 1 of 5 : State of the hypotheses in terms of the standard deviation. Round the standard deviation to four decimal places when necessary Step 2 of 5 : Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places. Step 3 of 5 : Determine the value of the test statistic. Round your answer to three decimal places. Step 4 of 5 : Make the decision. Step 5 of 5 : What is the conclusion?
Does buttered toast fall face down? Data was collected to test this. 40 slices of toast (each with butter on one side) were dropped (from the same height). 24 slices (60%) landed buttered side down. We would like to use the results of this study to determine if there is statistical evidence that toast tends to land buttered side down more than 50% of the time.
The mean and the variance of a sample of size 16 from normal population are 32 and 8, respectively. For testing the hypotheses H,:0%=46vsH, : 0> # 4.6 thetest statistic is: Select one: O a.22.83 O b.19.57 () ¢.29.35 O d.26.09
Deandre is in his first semester at a certain university and is taking a calculus course with a large enrollment. He just took the first midterm exam and is nervous about his score. Among all of the students in the course, the mean of the exam was 67 with a standard deviation of 3. Deandre scored a 62 on this exam. (a) Find the z-score of Deandre's exam score relative to the exam scores among all the students in the course. Round your answer to two decimal places. z=0 (b) Fill in the blanks to interpret the z-score of Deandre's exam score. Make sure to express your answer in terms of a positive number of standard deviations. Deandre's exam score was standard deviations (Choose one) ▼ the mean exam score among all students in the course. Calendar ... 80 F3 F4 F6 F7 F8 F9 F10 F11 云

A dentist wants to estimate the average number of patients coming into her clinic each day. She estimates the standard deviation is 6 patients per day. If she wants to use a random sample of previous days for her sample, how many days should she include to be 95% sure her estimate is off by no more than 0.3 patients per day?

SEE MORE QUESTIONS

Recommended textbooks for you

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

Elementary Statistics: Picturing the World (7th E…

Statistics

ISBN:

9780134683416

Author:

Ron Larson, Betsy Farber

Publisher:

PEARSON

The Basic Practice of Statistics

Statistics

ISBN:

9781319042578

Author:

David S. Moore, William I. Notz, Michael A. Fligner

Publisher:

W. H. Freeman

Introduction to the Practice of Statistics

Statistics

ISBN:

9781319013387

Author:

David S. Moore, George P. McCabe, Bruce A. Craig

Publisher:

W. H. Freeman

SEE MORE TEXTBOOKS