MULTIPLE CHOICE. Choose the One Alternative That Best Completes the Statement Or Answers

Exam Name______

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Suppose you were to collect data for the pair of given variables in order to make a scatterplot. Determine for each variable if it is the explanatory variable, the response variable, or whether it could be both. 1) Studying consisten tly, high grade point average 1) ______A) Studying both consistently: High grade point average: explanatory B) Studying both consistently: High grade point average: both C) Studying explanatory consistently: High grade point average: both D) Studying response consistently: High grade point average: explanatory E) Studying explanatory consistently: High grade point average: response

2) Teacher: weekly salary, teacher: years of experienc e 2) ______Tb A eot ) ah c hTe eac rhe :r: ye war es eof kex lpe yri en sce a: lex apl ran yat :or y Teacher: response weekly salary: Teacher: years of experience: explanatory D) Teacher: both weekly salary: Teacher: years of experience: both E) Teacher: explanatory weekly salary: Teacher: years of experience: both

Suppose you are to form a scatterplot by collecting data for the given pair of variables. Determine the likely direction, form, and strength. 3) Depth, water pressure 3) ______Pn A oo ) sfo ir tm i, vst ero ,n g Negative, nonlinear, moderate D) Negative, straight, moderate E) Positive, straight, strong

4) Student: grade point average, student: height (feet) 4) ______Nn, A oli ) ne dar i, rm eo cde tra ite o No direction, no form, very weak D) No direction, no form, strong E) Positive, no form, very weak

Find the correlation. 5) Two different tests are designed to measure employe e producti vity and dexterity. Several employe es are randoml y selected and tested with these results.

5) ______A ) -0.280 B) 0.471 C) 0.115 D) 0.986 E) 0 . 9

Solve the problem. A science instructo r assigns a group of students to investiga te the relations hip between the pH of the water of a river and its water's hardness (measure d in grains). Some students wrote these conclusio ns: "there was a very strong correlatio n of 1.47 between pH of the water and water's hardness. " Is the calculatio n of the correlatio n appropri ate? 6) ______Ys A eof ) sth :e w tat her ear e pd Hat a aco nlle dct ed tfr ho em th he asa rm de nri eve sr. No: there is little or no association. D) No: correlation must be equal to 1. E) No: correlation cannot be greater than 1.

7) A science instructo r assigns a group of students to investiga te the linear relations hip between the pH of the water of a river and its water's hardness (measure d in grains). Some students wrote these conclusio ns: "My correlatio n of -0.94 shows that there is almost no associati on between pH of the water and water's hardness. " Is the interpret ation of the correlatio n appropri ate? 7) ______N A osh ) :o w as a cst oro rn rg ere lla ati to in oin na ne oga fti ve -di 0re .cti 9o 4n. Yes: pH and hardness of water do not have the same units. D) Yes: a correlation of -0.94 shows a weak relation in a negative direction. E) No: the pH and the hardness of the water are data collected from the same river.

8) A science instructo r assigns a group of students to investiga te the relations hip between the pH of the water of a river and its water's hardness (measure d in grains). Some students wrote these conclusio ns: "there was a very strong correlatio n of 0.917 between pH of the water and water's hardness. " Is the calculatio n of the correlatio n appropri ate? 8) ______Nat A oio ) :n ha cs on ro ru eni lts. Yes: the pH and the hardness of the water are data collected from the same river. D) Yes: correlation is less than 1. E) No: there is little or no association.

Tell what the residual plot indicates about the appropriateness of the linear model that was fit to the data. 9)

9) ______Mri A oat ) de. eT lhe re ila sti o nns ohi tp is an po pnl rin oea pr. Model is appropriate.

10) ______Mis A oap ) dpro epri late . Model may not be appropriate. The spread is changing.

Answer the question appropriately. 11) A this regression. random sample of records of electricit y usage of homes gives the amount of electricit y used and size (in square feet) of 135 homes. A regressio n to predict the amount of electricit y used (in kilowatt- hours) from size has an R- squared of 71.8%. The residuals plot indicated that a linear model is appropri ate. Write a sentence summari zing what says about 11) ______Sex A ipla ) zin e71. 8% dof ithe fvar fiati eon rin eele nctri ccit ey susa ge. Differences in electricity usage explain 71.8% of the variation in the size of house. D) Size differences explain 71.8% of the variation in the number of homes. E) Size differences explain 28.2% of the variation in electricity usage.

12) The number of games won. relations hip between the number of games won by a minor league baseball team and the average attendan ce at their home games is analyzed. A regressio n to predict the average attendan ce from the number of games won has an = 29.9%. The residuals plot indicated that a linear model is appropri ate. What is the correlatio n between the average attendan ce and the 12) ______A ) 0.547 B) 0.837 C) 0.701 D) 0.089 E) 0 . 9

Use the model to make the appropria te predictio n. 13) A y would you predict would be used in a house that is 2273 square feet? random sample of records of electricit y usage of homes in the month of July gives the amount of electricit y used and size (in square feet) of 135 homes. A regressio n was done to predict the amount of electricit y used (in kilowatt- hours) from size. The residuals plot indicated that a linear model is appropri ate. The model is size. How much electricit 13) ______3 A 4kil ) 7ow 7att- . ho 6urs 1781.67 kilowatt-hours D) 159.8 kilowatt- hours E) 2567.8 kilowatt-hours

Answer the question appropriately. 14) A correlatio n of zero between two quantitat ive variables means that 14) ______r A ewil ) -l egu xara pnte re a elin sear sass ioci nati gon bet twe hen ethe tw do avar tiab ales. None of the above. D) there is no linear association between the two variables. E) we have done something wrong in our calculation of r.

Part II:

For each of the problems please do the following:

A) Write down the line of regression with context

B) Write down the correlation coefficient ( r value) with context

C) Write down the coefficient of determination (r2 )

1) 2) 2) The population of the city of Jackson for the past ten years is listed in the chart below.

a) What is the least square regression equation with context

______

b) What would the population be of Jackson when it is 60 years old? ______

c) What would the population be of Jackson when it is 100 years old? ______

d) How old would Jackson be if the population was 27,486.8?

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The table above shows the years of experience for eight technicians at Lewis Techomatic and the hourly rate of pay each technician earns. A) What is the least square regression line?

B) Predict the hourly rate of pay for a person who has 7years of experience.

C) How about for a person who has 12 years experience.