Mid Term Exam Review Part 2

If you could predict the future, what would you do?

Hurricane Katrina

Scatter Plots (used to display a trend)

An effective way to hunt for patterns or trends is to display the data as a scatter plot.

The difference between independent and dependent will be determined by insight. Typically, the IV comes first Ex pay vs hours worked Pay: DV and Hours: IV

Outlier

An outlier is a point separated from the main body of the data.

Todays Lab…..

Distance Vs Height Distance (m) Ramp Height (cm) (dependent) (independent)

Direct Variation

Consider working at McDonald’s You get paid $8.00 per hour

Hours 1 Pay ($) X 8 In Direct Variation, one variable equals a fixed multiple of the other.

Hours 1 Pay ($) X 8 This multiple is called the constant of variation (k)

Hours 1 Pay ($) X 8 The formula: P =8h

Pay vs Hours P H

How much would you get paid for 3.5 hours? P = 8 X 3.5 = 28

P H

How much would you get paid for 7 hours? P = 8 X 7 = 56

P H

Partial Variation

Consider working at East Side Mario’s You get paid $8.00 per hour. You also get paid a $20.00 shift gratuity.

Hours 1 Pay ($) = = = 100 X = 28 In Partial Variation, one variable equals a fixed multiple of the other, plus a constant value.

Written as an equation P = 8h + 20 Variable part Fixed part

Pay vs Hours P H

What if we draw 2 lines on the same graph? We create what is called a linear system.

P H

Engineers have created a mathematical measure for the steepness of a line Slope: The measure of a line’s steepness

Distance Time Steepness?Direction?Straight?

Rise Run Slope = Rise Run

Step Count Technique Count the number of steps going from left to right.

5 2 m = 5 2

-5 2 m = -5 2

First Differences Be sure to copy down all the text in black. All the colored text is just for reading and reflecting

TimeDistance Add a First Differences Column to your chart First Differences When the FDs are the same, the relationship is linear 2 – 0 = 2 4 – 2 = 2 6 – 4 = 2 8 – 6 = 2 Imagine the snake at 2 m / second

Use a TOVs with a FD column to determine if the following relationship is linear or not. In summary FDs are the same, then linear FDs are different, then non-linear

See sheet