In Chicago in the year 2000, there were approximately 1.053 million African Americans, 907 thousand whites (non-Hispanic), 754 thousand Hispanics, and 181 thousand others (other races or two or more races). What percentage of Chicagoans in 2000 were of Hispanic origin?

1.053 .907 .754 .181 2.895Total million

.754.26 or 26%

2.895

part

whole

Assignment 2

Day Bacteria% change in

decimal%

change% change in decimal

formula

0 360

1 5,760 15 1500 "=(B3-B2)/B2"

2 92,160 15 1500

3 1,474,560 15 1500

4 23,592,960 15 1500

5 377,487,360 15 1500

Activity 4 Problem

In 1994, Zaire’s per capita GNP was $125 (70% lower than it was in 1958).  What was Zaire’s per capita GNP in 1958?

What a lot of you did:

Notice, though,

$125*(1 .7) $212.5

$212.5*(1 .7) $63.75

*(1 .7) $125x

*(1 .7) $125x

Same as:

Multiply both sides by x:

Add x to both sides:

Factor out an x: $125 *(1 .7)x

$125 *(.3)x $125$416.67

.3x x

$125.7

x

x

$125 .7x x

$125 .7x x

Successive Percents

Let’s say you have $100 and you increase this by 5% to get to…

$100*(1+.05) = $105If you decrease $105 by 5% you get: $105*(1-.05) =$99.75What is the overall percentage change?Started with $100Ended with $99.75 $99.75 $100

.0025 or .25%$100

Dog Jeans are on sale for 40% off the retail price. The retail price is $40.00. If you have a coupon, you can receive an additional 20% off the sale price. What are the overall percentage savings?

The sale price: $40*(1-.4) = $24Determine the final price with coupon:$24*(1-.2) = $19.20

The overall percentage change??

Not 60%

Value Reference

Value Reference - Value New

($19.20 $40).52 or 52%

$40

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

Retail Price Sale Price Final Price withCoupon

Overall PercentageChange

Price Amount Saved

$40.00 - $16.00 = $24.00

$24.00 x.20 = $4.80

$24.00 - $4.80 = $19.20

$40.00 x.52 = $20.80

$40.00 - $20.80 = $19.20

$40.00 x .40 = $16.00

Absolute vs Relative

Quantities

• The absolute quantity is a measure of the absolute occurrence of the variable.

• The relative quantity is the absolute quantity divided by some other quantity.

• Three kinds of relative quantities…

Percentages

Fractions or percents are used when comparing part to total of the same type of variable. (example: percent of adults with HIV)

SortingAutosumChange to percent / decimal

Rates

Rates are used to compare different types of variables (example: tickets per person, miles per hour, or crimes per 1000 people)

Map it

Ratios

Ratios are used to compare the same type of variable from two sources.

California’s population is 33,872,000 and Oregon’s population is 3,421,000. Clearly CA’s population is larger but how many times larger?

33,872,000/3,421,000 = 9.90

The moon is 383 thousand kilometers away from earth. The sun is 149 million kilometers away. How many times further away is the sun than the moon?

Absolute or Relative?

I have 16 cheeseburgers. I have 100% more cheeseburgers than you.I have 2 times as many cheeseburgers as you.You have 8 cheeseburgers. I eat 3 cheeseburgers per hour.

Absolute or Relative?

I have 16 cheeseburgers. AbsoluteI have 100% more cheeseburgers than you. Relative

I have 2 times as many cheeseburgers as you. Relative

You have 8 cheeseburgers. AbsoluteI eat 3 cheeseburgers per hour. Relative