Resources

Resources

Estimate population size using proportions

Alderwoman Natalia polled a random sample of residents in her district about new affordable housing projects in the district. The results of the poll are most representative of which of the following populations?

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Maya's school is having a spring carnival. When Maya carries a bin of water balloons outside for the balloon toss, she trips and breaks

11

balloons. She counts the remaining water balloons, and there are

13

left. Which equation can you use to find the number of water balloons

w

in the bin before Maya trips?

the number of muskrats in a

144

acre area is estimated to be

2736

. What is the estimated population density

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19

muskrats per acre

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20

muskrats per acre

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21

muskrats per acre

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22

muskrats per acre

The area in thousands of square kilometers of

19

countries in East and Southeast Asia are shown in the dot plot. Each value is rounded to the nearest

250

thousand square kilometers. China, which has an area of

9

597

thousand square kilometers, was excluded from the data. If China were included, then which of the following changes would NOT occur?

For a science fair project, Anthony is trying to estimate the population of armadillidiidae bugs (more commonly known as roly polies) on his parents' property. Anthony traps

38

roly polies, marks them, and releases them. He then replaces the traps and ends up catching

490

19

of which are marked. To the nearest whole number, what is the best estimate for the roly poly population?

The wallaby is essentially a small kangaroo that is native to Australia. To monitor the wallaby population, scientists catch

70

wallabies and tag them. A month later, they capture

240

wallabies and notice that

28

of them are tagged. To the nearest whole number, what is the best estimate for the wallaby population?

Brennan, a farmer, orders a large box of ladybugs to control pests in his greenhouse. To make sure that he was shipped as many ladybugs as he ordered, he decides to figure out approximately how many ladybugs there are in the box. He catches

30

ladybugs, marks them with special paint, and returns them to the box. Then a little while later, he catches

390

ladybugs and counts

13

marked ladybugs among them. To the nearest whole number, what is the best estimate for the ladybug population?

For a research study,

65

marmots were tagged and set free. Later, the researchers returned to the site and found

17

tagged marmots out of the

340

marmots they counted. To the nearest whole number, what is the best estimate for the marmot population?

For a research project on rodents,

41

chipmunks were tagged and released. Later, researchers counted

320

chipmunks in the area. Of the chipmunks they counted,

16

had tags. To the nearest whole number, what is the best estimate for the chipmunk population?

Scientists captured, tagged, and released

47

ducks as part of a research study. A week later, the scientists returned to the area and found

23

tagged ducks out of the

230

ducks they counted. To the nearest whole number, what is the best estimate for the duck population?

The total cost of a new automobile priced at

\$26,372

including sales tax is

\$28,482

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Find the sales tax to the nearest percent.

Two surveyors estimate the height of a nearby hill. One stands

5\,\text{m}

away from the other on horizontal ground holding a measuring stick vertically. The other surveyor finds a ＂line of sight＂ to the top of the hill, and observes that this line passes the vertical stick at a height of

2.4\,\text{m}

. They measure the distance from the stick to the top of the hill to be

1500\,\text{m}

using laser equipment. Find, correct to the nearest metre, their estimate for the height of the hill.

Priya spends at least

3.5

hours practicing her English each week. If she spends

7

days a week practicing, what best describes the average number of hours she practices each day?

John volunteers on the weekend at the Central Library. As a school project, he decides to record how many people visit the library, and where they go. On Saturday,

468

people went to The Youth Wing,

324

people went to Social Issues, and

356

went to Fiction and Literature.

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On Sunday, the library had

1100

total visitors. Based on what John had recorded on Saturday, about how many people should be expected to go to Social Issues? Round your answer to the nearest whole number.

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In one town there are

25

drivers under the age of

21

. There are a total of

225

drivers in town. what is the fraction of drivers under

21

An online furniture store sells chairs for

\$ 50

each and tables for

\$ 250

each. Every day, the store can ship no more than

32

pieces of furniture and must sell at least

\$ 3200

worth of chairs and tables. If

9

tables were sold, determine all possible values for the number of chairs that the store must sell in order to meet the requirements.

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The annual energy consumption of the town where Camilla lives increases at a rate that is proportional at any time to the energy consumption at that time.

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The town consumed

4

4

trillion British thermal units (BTUs) initially, and it consumed

5

5

trillion BTUs annually after

5

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What is the town's annual energy consumption, in trillions of BTUs, after

9

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1

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6

6

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32

8

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41

8