Researchers doing a study comparing time spent on social media and time spent on studying randomly sampled 200 students at a majoruniversity. They found that students in the sample spent an average of 2.3 hours per day on social media and an average of 1.8 hours perday on studying. If all the students at the university in fact spent 2.2 hours per day on studying, with a standard deviation of 2 hours, then:Select one:O a. the sample average is unbiased, since a proper random sample was taken from the population.O b. the sample average of 1.8 hours studying is biased, because it is not equal to 2.2.Oc. there is not enough information to choose an answer option.Od. the sample average is in error since, clearly, students study more.

Consider the random variables X1, X2, ..., Xn as a random sample from a population with mean µ. The…

Answered: Researchers doing a study comparing…

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 and your two friends paid the following amounts for a new MP3 player: $165, $210, and $225. A. What is the mean and standard deviation of the population of you and your friends? Mean (round to the nearest penny): u = $200 Standard Deviation (round to the penny): o = $31.22 B. Complete the table using the sample size of two prices, with replacement. x1, x2 Ex 165, 330 165 165 165, 375 187.5 210 165, 390 195 225 210, 187.5 375 165 210, 210 420 210 210, 435 217.5 225 225, 390 195 165 225, 435 217.5 210 225, 450 225
An operations manager wants to know whether the maintenance of a filling machine for 2 litre milk bottles has made a difference in the average fill of the milk bottle. She randomly selects 25 bottles before the maintenance service, and 25 bottles after the maintenance service has taken place. The resulting SPSS output is shown below: Paired Samples Statistics Mean N Std. Deviation Std. Error Mean Pair 1 After Service 2.0029 25 .01142 .00228 Before service 1.9687 25 .03193 .00639 Paired Samples Test Paired Differences t df Sig. (2- tailed) Mean Std. Deviation Std. Error Mean 95% Confidence Interval of the Difference Lower Upper Pair 1 After Service – Before service .03420 .03503 .00701 .01974 .04866 4.882 24 .000 Question: Based on the output choose the most accurate answer
K.Brew sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet. Random samples of sales receipts were studied for mail order sales and internet sales, with the total purchase being recorded for each sale. A random sample of 18 sales receipts for mail order sales results in a mean sale amount of $81.30 with a standard deviation of $16.25 . A random sample of 9 sales receipts for internet sales results in a mean sale amount of $67.00 with a standard deviation of $15.25 . Using this data, find the 98% confidence interval for the true mean difference between the mean amount of mail order purchases and the mean amount of internet purchases. Assume that the population variances are not equal and that the two populations are normally distributed. Step 2 of 3 : Find the standard error of the sampling distribution to be used in constructing the confidence interval. Round your answer to two decimal places.
Suppose a Realtor is interested in comparing the asking prices of midrange homes in Peoria, Illinois, and Evansville, Indiana. The Realtor conducts a small telephone survey in the two cities, asking the prices of midrange homes. À random sample of 21 listings in Peoria resulted in a sample average price of $116,900, with a standard deviation of $2,300. A random sample of 26 listings in Evansville resulted in a sample average price of $114,000, with a standard deviation of $1,750. The Realtor assumes prices of midrange homes are normally distributed and the variance in prices in the two cities is about the same. The researcher wishes to test whether there is any difference in the mean prices of midrange homes of the two cities for alpha = .01. The degrees of freedom for this problem are 20 25 46 45 43 O O O O O
A study compared the cost of restaurant meals when people pay individually versus splitting the bill as a group. In the experiment half of the people were told they would each be responsible for individual meals costs and the other half were told the cost would be split equally among the six people at the table. The 24 people paying individually had a mean cost of 37.29 Israeli shekels with a standard deviation of 12.54, while the 24 people splitting the bill had a higher mean cost of 50.92 Israeli shekels with a standard deviation of 14.33. The raw data can be found in SplitBill and both distributions are reasonably bell-shaped. Use this information to find a 95 % confidence interval for the difference in mean meal cost between these two situations. Click here for the dataset associated with this question. Round your answers to two decimal places. The 95 % confidence interval is ! to i
An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was $421, $469, $416, $232 Compute the range, sample variance, and sample standard deviation cost of repair.
The average McDonald's restaurant generates $3.6 million in sales each year with a standard deviation of 0.9. Trent wants to know if the average sales generated by McDonald's restaurants in Kentucky is different than the worldwide average. He surveys 27 restaurants in Kentucky and finds the following data (in millions of dollars): 4.1, 2.8, 4.4, 4.5, 5.3, 5, 3.7, 2.9, 3.8, 4.8, 3.6, 2.3, 3.7, 2.9, 2.9, 4, 1.1, 5.2, 2.9, 5, 4, 4, 5.9, 3.2, 2.2, 4.3, 3.8 Perform a hypothesis test using a 3% level of significance. Step 1: State the null and alternative hypotheses. Ho: [? v] ? v На: ? ? v (So we will be performing a Select an answer test.) Step 2: Assuming the null hypothesis is true, determine the features of the distribution of point estimates using the Central Limit Theorem. By the Central Limit Theorem, we know that the point estimates are Select an answer v with distribution mean and distribution standard deviation Step 3: Find the p-value of the point estimate. P( ? v ? v = P( ? ♥ ?…
Six students took a chemistry quiz. Their scores are listed below. Calculate the experimental standard deviation. Quiz scores: 16, 13, 14, 9.0, 18, 21
Salvatore, as the director of a regional bank, is concerned about the wait times of customers at the four branches. He randomly selects 48 patrons at each branch and records the waiting time for each patron. The results of the samples are shown below. The Alvrine branch has a mean waiting time of 13.49 minutes with a standard deviation of 1.97 minutes.The Durham branch has a mean waiting time of 12.61 minutes with a standard deviation of 2.89 minutes.The Hanover branch has a mean waiting time of 11.06 minutes with a standard deviation of 2.46 minutes.The Mascomonet branch has a mean waiting time of 12.89 minutes with a standard deviation of 3.12 minutes.
The cost of unleaded gasoline in the Bay Area once followed an unknown distribution with a mean of $ 4.87 and a standard deviation of $ 0.05. A sample of 15 Bay Area gas stations are randomly chosen. We are interested in the average cost of gasoline for the 15 service stations. The distribution to use for the average cost of gasoline for the 15 service stations is: Select one: a. N (4.87, 0.0129) b. N (0.3247, 0.0006) c. N (4.87, 0.0033) d. N (4.87, 0.0002) e. N (0.3247, 0.0033)
An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was $421, $469, $416, $232 . Compute the range, sample variance, and sample standard deviation cost of repair.
In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66 What is the standard deviation?

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