Given the following sample data: x 420 610 625 500 400 450 550 650 480 565 y 2.80 3.60 3.75 3.00 2.50 2.70 3.50 3.90 2.95 3.30 1. Calculate the covariance and the correlation coefficient. Discuss what they represent and why they are used in statistics, especially the business world. 2. Briefly discuss the relationship between x and y and what do these statistics tell you.

What is the relationship between the number of minutes per day a woman spends talking on the phone and the woman's weight? The time on the phone and weight for 7 women are shown in the table below. Time 14 40 24 76 74 87 84 Pounds 124 122 116 178 181 174 167 a. Find the correlation coefficient: r = Round to 2 decimal places. b. The null and alternative hypotheses for correlation are: Ho: ? ▼ Hj: ? v The p-value is: (Round to four decimal places) c. Use a level of significance of a = 0.05 to state the conclusion of the hypothesis test in the context of the study. O There is statistically insignificant evidence to conclude that there is a correlation between the time women spend on the phone and their weight. Thus, the use of the regression line is not appropriate. O There is statistically insignificant evidence to conclude that a woman who spends more time on the phone will weigh more than a woman who spends less time on the phone. O There is statistically significant evidence to…

Which of the following best describes the Pearson correlation for these data? X Y 2 5 5 1 3 4 4 2

Let x be the average number of employees in a group health insurance plan, and let y be the average administrative cost as a percentage of claims. Suppose a random sample of employees gave the following information. X 12 8 14 32 73 y 50 45 35 28 16 Would you say the correlation is low, moderate, or strong? Positive or negative? If necessary, draw a scatter diagram of the given data. O strong and negative O moderate and positive strong and positive O low and negative

A student of Engineering conducted a research to determine the correlation between performance of 2 lathes in the workshop. Assessments were conducted on weekly basis, and the following data were obtained. Calculate the coefficient of correlation using Karl Pearson's method, and discuss the level of the relationship. Table 2. The performance of the lathes on weekly basis. Week(s) 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th Lathe A 42 48 40 28 46 90 28 56 16 22 Lathe B 56 78 72 24 60 42 36 82 28 34 良

Given the table below, use your calculator to find the Correlation Coefficient xx 7.1 9.6 8.9 4.5 2.9 4.4 yy 17.9 25 22.4 18.6 12.3 15.9

Use the data values in the table below to calculate the correlation between the variables x and y. Hint: Use your calculator to do this, you do not need to compute this by hand. y 4 19.34 5 19.35 6 20.86 7 24.57 8 23.08 9 23.89 10 28.6 Give your answer to three decimal places.

Two separate tests are designed to measure a student's ability to solve problems. Several students are randomly selected to take both tests and the results are shown below.    Test A (x) 43   65 73 34 99 78 65 Test B (y) 39 60 62 20 85 70 54   1. Calculate r, the linear correlation coefficient.  Identify the values for each part below. Part a.   The value of n   Part b.   The sum of the x-values  Part c.   The sum of the y-values  Part d.    The sum of the x-squared values   Part e.    The sum of the y-squared values   Part f.    The sum of the (xy) values   Part g.    The final value of r rounded top three decimal places

Assumptions: Data are normally distributed.   Your job, solved this problem: 1. Is there a significant RELATIONSHIP between X and Y?  Explain! 2. calculate the correlation coefficient. 3. Is there a significant EFFECT between X and Y? Explain!

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