1. HW: Measures of Variability Wkst
Tuesday, 5/9/17
Write the IC and HW in your planner.
IC: IQR
HW: Measures of Variability Wkst
Materials
Pencil & grading pen
Planner
Marker
Data Analysis Wkst
Data Analysis Activity 1

2. Bellwork Label the 5 indicated parts on the box-and-whisker plot.
3rd/Upper Quartile
1st/Lower Quartile
Median 2) 3) 1)
Upper Extreme or Extreme 4)
Whisker 5)
6) Find the range of the middle half of the data in the box-and-whisker plot above.
8 – 4 = 4

3. Measures of Variability
7.SP.4
Objective: TSWBAT find the measures of variability and use them to interpret/analyze data.
3/17/16
Ch. 10.7
Measures of Variability
Range
Interquartile Range (IQR)

4. Range : The difference between the greatest number and lowest number
= 48
l l l l l l l l l l l

5. IQR = 94 – 76
= 18
l l l l l l l l l l l

6. Ex. 6: Find the measures of variability for the data in the table.
Range:
Median:
Q1:
Q3:
IQR:
61 – 0 = 61 35 61 31 34 32 24 39 38
U.S. Summer Olympic Silver Medals 34
27.5
38.5
38.5 – 27.5 =
11.0
0, 24, 31, 32, 34, 35, 38, 39, 61
24+31=55
38.5
55  2 = 27.5
Use the measures of variability to describe the data.
There is not much variability in the data because the IQR is only 11, but the overall range is 61. This means half of the data values are close to the median.
If we were to draw a box & whisker plot, the box would be small compared to the whiskers!

7. Ex. 7: Find the measures of variability for the data in the table.
Swimming
261
Soccer
234
Football
222
Basketball
210
Tennis
183
Downhill Skiing
150
Volleyball 84
Raquetball
228
Range:
Median:
Q1:
Q3:
IQR:
261 – 84 = 177
# Calories Burned for 30 Min.
216
166.5
231
231 – =
64.5
84, 150, 183, 210, 222, 228, 234, 261
=333
=462
333  2 = 166.5
462  2 = 231
=432
432  2 = 216

8. Use the measures of variability to describe the data.
Ex. 7: Find the measures of variability for the data in the table.
Swimming
261
Soccer
234
Football
222
Basketball
210
Tennis
183
Downhill Skiing
150
Volleyball 84
Raquetball
228
Range:
Median:
Q1:
Q3:
IQR:
261 – 84 = 177
# Calories Burned for 30 Min.
216
166.5
231
231 – = 64.5
84, 150, 183, 210, 222, 228, 234, 261
=333
=462
333  2 = 166.5
462  2 = 231
Use the measures of variability to describe the data.

9. Closure What are the two measures of variability? ___________________
What do the measures of variability do for us?

10. Bellwork red blue tails 5 or 6 1st 2nd x = 1st 2nd x =
1) Find the probability of drawing a red marble from a bag of 6 red and 4 blue marbles, replacing it, and then drawing a blue marble.
red
blue
1st nd x =
2) Find the probability of a flipped coin landing on tails and rolling a 5 or 6 on a number cube.
tails
5 or 6
1st nd x =

11. Bellwork green blue 1st 2nd x =
3) Imagine you have a bag of candy with 2 green jolly ranchers, 5 blue jolly ranchers, and 1 red jolly rancher. What’s the probability you grab a green jolly rancher, eat it, and then blindly reach in again and grab a blue jolly rancher?
green
blue
1st nd x =

12. Bellwork Pencil Pen 1st Pick 2nd Pick
4) Jill has 2 pencils and 8 pens in her backpack. What is the probability that Jill will randomly choose a pencil out of her backpack and then, without replacing it, choose a pen?
Pencil
Pen
1st Pick 2nd Pick
At first, there are 10 total writing utensils. After you pick a pencil, there are only 9 things left. However, all of the gel pens are left. x =