Regression Assignment

Alright crew, as your foreman at Gerken Paving, I'm always checking how much water we mix into our concrete and how tough it turns out. The number that tells us how these two things are connected is called the correlation coefficient, and it's shown by the letter _______.

• r

• r^2

• m

• b

Alright crew, as your foreman here at Gerken Paving, I’ve been looking at how long each of us has been on the job and what we’re making per hour. If the correlation coefficient between years of experience and hourly wage is r=0.85, what does that tell us about how these two things are connected?

• There is a strong positive correlation between years of experience and hourly wage.

• Hourly wage decreases as years of experience increases.

• There is no correlation between years of experience and hourly wage.

• Years of experience has a negative impact on hourly wage.

Match the following

• weak negative correlation

• +0.99

• weak positive correlation

• -0.97

• strong positive correlation

• -0.44

• strong negative correlation

• +0.31

Tags

CCSS.HSF.IF.A.2

Listen up, crew. Out here at Gerken Paving, every time the temperature climbs, I see my concrete setting faster, and it happens like clockwork. If someone says there's a perfectly negative correlation between temperature and set time, what are they really saying?

• implies a coefficient of determination of –1.0.

• means that there must be a slope of –1.0.

• says that for every one additional unit of the variable on the x–axis, the variable on the y–axis must move down one additional unit.

• means that the r–value is is exactly 1.0.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

Alright crew, listen up! Out here at Gerken Paving, which of these situations have I seen that shows a negative correlation?

• The more time I spend using a concrete saw, the less battery is left in the saw.

• The more hours I spend preparing a site, the better the quality of the finished pavement.

• The more truckloads of concrete delivered, the more pavement I complete.

• The color of my safety vest and my skill level.

Alright crew, out here at Gerken Paving, I’ve been keeping track of how the temperature’s messing with our concrete drying times. Here’s what I’ve jotted down:

Temperature (x) (°F), Drying Time (y) (hours)

50 24

60 20

70 18

80 15

90 12

1. What’s the equation for the line that best fits this data, so we can predict drying times based on temperature?

• y = -0.29x + 38.1

• y = 38.1x - 0.29

• y = 38.1x + 0.9917

• y = -0.29x - 0.9959

Alright crew, listen up. Out here at Gerken Paving, we need to know how the heat messes with our concrete drying times. I got this formula:

y = -0.29x + 38.1

What’s that slope mean for us on the job?

1. 
   

• The slope of -0.29 indicates that for each 1 degree increase in temperature, the drying time decreases by 0.29 units.

• The slope of -0.29 suggests that a decrease in temperature leads to a decrease in drying time by 0.29 units.

• The slope of -0.29 indicates that the drying time is constant regardless of temperature changes.

• The slope of -0.29 means that for each 1 degree increase in temperature, the drying time increases by 0.29 units.

Alright crew, listen up. Out here at Gerken Paving, we need to know how the heat is gonna mess with our concrete drying times. We got this formula:

y = -0.29x + 38.1

If it’s 75°F out, what’s the drying time gonna be? Let’s figure it out so we can plan the rest of the job.

1. 
   

• 16.35

• 25.0

• 12.75

• 20.5

Alright crew, listen up. Out here at Gerken Paving, we gotta know how long this concrete's gonna take to dry, and it all depends on the heat. The formula we're using is y = -0.29x + 38.1, where x is the temperature in degrees Fahrenheit, and y is the drying time in hours.

If it's a scorching 100°F today, how many hours before we can walk on that slab?

• 5.3 hours

• 9.1 hours

• 12.7 hours

• 15.0 hours