statistics online exam help

A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the .10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree?

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Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. At the .01 level of significance, is there sufficient evidence to conclude that a difference exists between the mean number of volunteer hours per week for male and female college students?

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Two independent samples of sizes n1 = 50 and n2 = 50 are randomly selected from two populations to test the difference between the population means,  . The sampling distribution of the sample mean difference,  is: see snapshot

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An agent for a residential real estate company in a large city would like to be able to predict the monthly rental cost of apartments based on the size of the apartment. Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook Apartments.xlsx.  Apartments.xlsx At the .05 level of significance determine if the correlation between rental cost and apartment size is significant.

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The standard error of the estimate, sest, is essentially the

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The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. .

Compute the value of the sample correlation coefficient between weekly sales and shelf space.

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Outliers are observations that

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The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars.

What is the estimated regression equation? see snapshot

A. = 1.45 + 0.724x
B. = 2.63 + 0.724x
C. = 2.63 – 0.174x
D. = 1.45 + 0.074x

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Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  A survey of employees at a company finds that 32 of the 88 employees who drive to work were ever late during the past year, and 18 of the 64 employees who took public transportation were ever late during the past year.  At α = 0.10, is there a difference between the proportion of employees who drove who were ever late and the proportion of employees who took public transportation who were ever late?  Find the test value for the difference in the proportion of employees who were ever late for work in the past year. Answer:  Round your answer to two decimal places.  What is your decision for this test?  1. The test value is greater than the critical value of 1.960. 2. The test value is less than the critical value of 1.645.  3. The test value is greater than the critical value of 1.282.  4. The test value is less than the critical value of 1.960.  Answer:    Enter only a 1, 2, 3 or 4 for your answer.

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook Apartments.xlsx. Using the estimated regression equation found by using size as the predictor variable, find a point estimate for the average monthly rent for apartments having 1,000 square feet of space. Place your answer, rounded to the nearest whole dollar, in the blank.   When entering your answer do not use any labels or symbols. Simply provide the numerical value. For example, 123 would be a legitimate entry. Apartments.xlsx

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  A company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx  Treating ILE as the response variable, use regression to fit a straight line to all 18 data points. What values for the intercept (a)  and slope (b) do you obtain? Place your answers, rounded to 3 decimal places, in the blanks provided.  Do not use any stray punctuation marks.  For example, 34.567 would be a legitimate entry.  intercept (a) =   slope(b) =

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  Two teams of workers assemble automobile engines at a manufacturing plant in Michigan. A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies. A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies.  If you are interested in determining if there is sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies, what is the p-value associated with such a test of hypothesis?  Place your answer, rounded to 4 decimal places, in the blank. For example, .0123 would be a legitimate entry.

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  Two teams of workers assemble automobile engines at a manufacturing plant in Michigan. A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies. A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies.  If you are interested in determining if there is sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies, what is the test value you would use to conduct such a test of hypothesis?  Place your answer, rounded to 2 decimal places, in the blank. For example, 2.34 would be a legitimate entry.

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.  Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.  For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.  A professor gives an exam for which there are two versions, A and B.  Each student in the class is given one randomly selected version of the exam.   After the exam, the professor wishes to determine if there is a difference in the level of difficulty of the two versions by determining if there is a significant difference in the mean scores.  Assume α = 0.05.

What is the test value for this hypothesis test? Answer:     Round your answer to two decimal places. What is/are the critical value(s) for this hypothesis test?  If there are two critical values, give only the positive value. Answer:     Round your answer to two decimal places. What is the conclusion for this hypothesis test?  Choose one. 1.  There is not sufficient evidence to show that one version of the exam is more difficult than the other. 2.  There is sufficient evidence to show that one version of the exam is more difficult than the other. Answer:     Enter only a 1 or 2 for your answer.

When the necessary conditions are met, a two-tail test is being conducted to test the difference between two population proportions. The two sample proportions are p^1 = 0.35 and p^2= 0.42, and the standard error of the sampling distribution of P^1 – p^2  is 0.054. The calculated value of the test statistic is 1.2963.

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A simple linear regression equation is given by y’ = 5 + 3x. The predicted value of Y when X = 3 is 5.

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In simple linear regression analysis, the relationship between the response variable Y and the explanatory variable X is a straight line. This means that all data points lie on the line.