### Find the sample correlation

Assignment Help Basic Statistics
##### Reference no: EM131069878

1. The following table represents frequency counts of types of transportation used by the publishing and computer hardware industries. Analyse the data to determine whether the transportation mode used to ship goods independent of type of industry? (α = 0.01)

 Transportation mode Industry Air Train Truck Publishing 32 12 41 Computer Hardware 5 6 24

2. A consulting firm presents a one-week training on reputation management to various clients. The training seminar is sometimes presented to high-level managers, sometimes to mid-level managers, and sometimes to low-level managers. Suppose the data below are some randomly selected scores from different levels of managers who attended the training.

 High (x1) Medium (x2) Low (x3) 7 9 6 7 9 5 7 10 5 9 8 8 8 8 4 10 7 8 X-1 = 7.6 x-2 = 8.857 x- = 7.5 x-3 = 5.833

a. Given that the SST (Sum of Squares Total) is 48.5, set out the analysis of variance (ANOVA) table.

b. Stating your null and alternative hypotheses, test if there is a significant difference between the exam scores according to manager level (α = 0.05).

3. A manager believes that business trip costs to New York increased significantly between 2004 and 2014. To test this belief, the manger samples 51 business trips from the company's record for 2004 and finds that the sample average was 190\$ per day with a population standard deviation of 18.5\$. The manager selects a second random samples of 47 business trips from the company's records for 2014 and finds that the sample average was 198\$ per day with a population standard deviation of 15.6\$.

a. Can the manager conclude that the average trip expenses increased significantly between 2004 and 2014 (α = 0.01)?

b. Would your decision change if the significance level was 5%?

c. Assume that the auditor did not know the population standard deviations of the trip expenses to New York in 2004 and 2014. Moreover, he/she obtained the sample standard deviations for 2004 and 2014 as 20\$ and 19\$ (variances can be assumed equal), respectively. At 5% significance level, can the auditor conclude that an average trip expense has increased since 2004?

4. A professor wants to compare the students' midterm and final exam results. For a random sample 10 students, the scores obtained are as follows.

 Midterm (x) Final (y) 50 66 40 57 45 87 48 45 53 61 41 49 77 88 9195 91 668 63 4123 40

Σx = 540,              Σy = 647,              Σxy = 37522,       Σx2 = 33026,        Σy2 = 44915

a. Find the sample correlation between the midterm and final examination results.

b. Test at 1% level if there is a significant correlation between midterm and final examination results of the students.

### Write a Review

#### Find standard deviation for number of students

What is the Standard Deviation of the Probability Distribution that would list the number of students (from 0 to 84) and the probability of each.

#### Difference in model fit and independence of residuals

Are the residuals from such a regression independent? Is there a difference in model fit and independence of residuals when using infant death rate as a response variable?

#### The lifetime of a semiconductor laser has a lognormal

the lifetime of a semiconductor laser has a lognormal distribution and it is known that the mean and standard deviation

#### Correlation coefficient-regression equation

Compute the coefficient of correlation and the coefficient of determination and determine the regression equation.

#### How should the editor revise the probabilities

If the proposal textbook receives favorable reviews, how should the editor revise the probabilities of the various outcomes to take this information into account?

#### Small sample confidence interval for population mean

Your quality control department has just analyzed the contents of 20 randomly selected barrels of materials to be used in manufacturing plastic garden equipment.

#### What is the probability that at least one of the shifts

a production facility employs 20 workers on the day shift 15 workers on the swing shift and 10 workers on the graveyard

#### Probability that a randomly selected time interval

What is the probability that a randomly selected time interval between eruptions is longer than 108 minutes?

#### A national water expert is interested

A national water expert is interested in determining the average amount of lead (in ppm, parts per million) that is found in the Houston, Texas drinking water. To conduct her research, she considers only those residential households within the city l..

#### Proportion of applicants that fail the test

As a condition of employment, Fashion Industries applicants must pass a drug test. Of the last 220 applicants 14 failed the test. Develop a 99 percent confidence interval for the proportion of applicants that fail the test.

#### A research study showed that 50 of workers change jobs

a research study showed that 50 of workers change jobs within 2 years of employment. george took a random sample of 100

#### Multiple comparison procedures

Multiple comparison procedures are going to be done using the Bonferroni method with = 0.05. The value of t** is 2.4667. Which of the following is the appropriate conclusion from carrying out these multiple comparisons?

#### Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!