Quick Start Expectations1. Fill in planner and HWRS

HW: SP p. 22 #9-162. Get a signature on HWRS3. On desk: journal, LS kit, Toolkit, calculator

4. Warm Up: Find the inter-quartile of these numbers (format it correctly):

22, 23, 44, 45, 33, 33, 8, 30

If you finish, find the range, mean, mode, and MAD

Step 1: Write them in order from least to greatest.

8, 22, 23, 30, 33, 33, 44, 45

Step 2: Find the median of the data. • Since there are two numbers in the middle we have to find the mean of the two.

(30 + 33) / 2 = 31.5Step 3: Find the Upper Quartile: UQ: 44 + 33 = 77 /2 = 38.5Step 4: Find theLower Quartile: LQ: 23 + 22 = 55 /2 = 22.5Step 5: Identify the middle half of the data from the (UQ) to (LQ) is

the inter-quartile range: IQRUQ – LQ = IQR. 38.5 – 22.5 = 16

31.5

UQ

38.522.5

LQ

22, 23, 44, 45, 33, 33, 8, 30

8, 22, 23, 30, 33, 33, 44, 45

Range

Mean

Mode

MAD

p. 16

How do you think the roller-coaster census data were collected?

Use on tonight’s HW!

How might you decide which are faster, steel-frame roller coasters or wood-frame roller coasters?

Range = 68 mi/h

Range = 41 mi/h

Mean = 55.03 mi/h

Mean = 52.6 mi/h

Median = 54.5 mi/h

Median = 53 mi/h

IQR = 28 mi/h

IQR = 10 mi/h

• IQR for steel-frame is more than twice the IQR for the wood-frame

• The median of the steel-frame is greater than the median of the wood-frame

• The middle 50% of the speeds for steel-frame are more variable than the middle 50% for wood-frame

Box-and-Whisker Plots

At least 25% of the steel-frame coasters have speeds that are faster than those of wood-frame coasters.

• The measures of center for steel-frame and wood-frame coasters are somewhat similar.

• Speeds of steel-frame coasters vary greatly.• Measures of spread (specifically IQR) show that at

least 25% of the steel-frame coasters have speeds that are faster than those of wood-frame coasters.