Quiz #5 STA2023 Linear Regression and Correlation

Name______Times/Days attend class______Date______Provide all of your work and answers in the spaces provided. However, you may attach additional work if you want to. Show all work for full credit . Your submitted quiz should not be a rough draft. You are allowed to seek out help from the Math Support Center, study groups, and/or the class instructor, but you must submit only your own work: do not copy! Remember, even though you may work with other people, you are graded individually. Write up your final draft by yourself and in your own style. Your work/responses must be your own. There are two printed pages to this quiz.

Busch Gardens Africa, an amusement park located in Tampa, FL, had 7 operating roller coasters as of July 13, 2006. The following is the list of these roller coasters with corresponding information. Information taken from Database: http://www.rcdb.com/pd15.htm

Duration in Roller Coaster Length in feet Height in feet Speed in mph seconds Coaster Type

Cheetah Chase 1214 46 28 110 Sit-Down

Gwazi 3400 90 50 150 Sit-Down

Kumba 3978 143 60 174 Sit-Down

Montu 3983 150 60 180 Inverted

Python 1250 70 50 70 Sit-Down

Scorpion 1805 65 50 135 Sit-Down

SheiKra 3188 200 70 180 Sit-Down

1 1. Make a scatterplot of Length versus Duration (you do not have to turn in the scatterplot) and note that the form is linear. a. (4 pts.) Write down the equation for the line of regression.

b. (4 pts.) Suppose that you ride a new roller coaster on its opening day at Africa and timed the ride to be exactly 2 minutes long. Predict the length of this new roller coaster (round your answer to the nearest foot).

c. (3 pts.) State the value of the correlation and describe specifically how this value is used to help you determine the strength or weakness of the linear scatterplot.

2. Make a scatterplot with Height as the explanatory variable and Speed as the response variable (you do not have to turn the scatterplot in). a. (5 pts.) State and interpret the association for this scatterplot.

b. (7 pts. total) i. State the value of the slope of the best fit line:______.

ii. Interpret the slope of the best fit line with regards to the story problem situation. Remember to use units of measure in your answer.

c. (2 pts.) What percent of the variation in Speed of the roller coasters at Busch Gardens Africa can be explained by their Height? Show what made you decide.

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