Q3 Percent

Question 1

How to find the percent?

Answer 1

(Portion / Whole) x 100

Question 2

Percent is easier to understand than . . .

Answer 2

Raw numbers

Question 3

Normalization

Answer 3

Standardizes number of different scales or times to enable fair comparisons

Question 4

If California has 9 national parks, and the rest of the nation has 52, what percent does California have?

Answer 4

52 + 9 = 61 [Whole]
9/61 = .148 x 100 = 14.8%

Question 5

Percent means . . .

Answer 5

Per 100

Question 6

Portion of the whole enables . . .

Answer 6

• Large numbers to be simplified
• Keeps us from confusing raw dominance with proportion

Question 7

Percent change formula

Answer 7

((New number - Old number) / Old number) x 100
“NOO”

Question 8

How to find percentage points

Answer 8

Subtract the two percents

Question 9

The old number

Answer 9

• Is always the one you’re comparing against
• The one after “than”

Question 10

What percent do you save on two pairs of $1.00 socks if the sale is Buy One, Get One 50% Off?

Answer 10

• First pair is $1.00
• Second pair is half off, so it’s $0.50
• You save $0.50
• 0.50 / 2.00 = 25%
• You save 25%

Question 11

Your favorite style of athletic shoes, normally $90, are now 30% off. How much will you pay?

Answer 11

$90 x .30 = $27
$90 - $27 = $63

Question 12

The pizza cost $26.87. If you add an 18% tip, how much is the bill?

Answer 12

$26.87 x .18 = $4.84
$26.87 + $4.84 = $31.71

Question 13

You spent $320 on coffee last semester. You are determined to cut your coffee spending this semester by 20%. How much could you spend on coffee?

Answer 13

$320 x .80 = $256

Question 14

Percent decrease

Answer 14

Cannot exceed 100 percent

Question 15

Percent increase

Answer 15

CAN exceed 100 percent

Question 16

What to do if the numbers are small

Answer 16

The relative becomes overstated and the absolute difference is a fairer comparison

Question 17

Inflation

Answer 17

• Allowing for inflation enables a fair comparison
• Another type of normalization

Question 18

Account for inflation when . . .

Answer 18

Comparing single units of money over 10 years or more

Question 19

What already has inflation baked in?

Answer 19

Two units of money over 10 years or more

Question 20

Percentile

Answer 20

Divides all things into 100 equal boxes

Question 21

What does scoring a 1340, placing you in the 90th percentile on the SAT, mean?

Answer 21

A score of 1340 was equal to or better than 90% of those who took the SAT

Question 22

Percentile involves . . .

Answer 22

Median (50th percentile)

Question 23

Quartile

Answer 23

• Four equal sized boxes
• Each has a name, ranging from Q1 to Q4

Question 24

Quintile

Answer 24

Five equal sized boxes

Question 25

Decile

Answer 25

Ten equal-sized boxes

Question 26

Upper decile

Answer 26

Upper 10%

Question 27

Upper quintile

Answer 27

Upper 20%

Question 28

Upper quartile

Answer 28

Upper 25%

Question 29

Poverty

Answer 29

• An overall median can be skewed by poverty
• Poverty should not be a major factor if only looking at the top decile