Spoonful SamplerData & Chance · statistics and probability

Tastes one spoonful to judge the pot: samples and studies.

Samples and Studies

Samples and studies. In MathBound, the free Algebra I adventure game, Spoonful Sampler asks these problems, and the only way past is to solve them.

Part of More topics: taught by some textbooks beyond the usual course.

10 questions, no sign-up, nothing saved. Climbs from the basics to harder questions.

What you will practice

Sampling and Studies. Name the population, the sample and the sampling method (random, systematic, stratified, cluster, convenience, self-selected).

Made by the game’s own question engine. Try each one, then open its steps.

A

high

school

has

140

freshmen,

80

sophomores,

320

juniors

and

80

seniors.

A

stratified

sample

of

31

students

takes

the

same

fraction

of

each

grade.

How

many

sophomores

are

in

the

sample?

Show the worked steps

$The$ $school$ $has$ $620$ $students,$ $and$ $31$ $of$ $620$ $is$ $1$ $in$ $every$ $20 .$
$1$ $in$ $every$ $20$ $of$ $the$ $80$ $sophomores$ $is$ $\frac{80}{20} = 4.$

Answer: $4$

At

a

factory,

the

manager

wants

to

know

what

the

workers

think

of

a

new

shift

plan,

and

asks

70

of

them,

chosen

at

random.

What

is

the

sample?

Show the worked steps

$The$ $sample$ $is$ $the$ $part$ $of$ $the$ $population$ $that$ $is$ $actually$ $asked.$
$the$ $70$ $workers$ $who$ $were$ $asked$

Answer: $the$ $70$ $workers$ $who$ $were$ $asked$

To

find

out

how

much

the

people

in

a

city

exercise,

a

researcher

asks

50

people

chosen

at

random

from

the

whole

city.

Is

the

sample

biased?

$No:$ $everyone$ $in$ $the$ $whole$ $city$ $had$ $the$ $same$ $chance$ $to$ $be$ $chosen$
$Yes:$ $people$ $at$ $a$ $gym$ $exercise$ $more$ $than$ $most$ $people$ $in$ $the$ $city$
$Yes:$ $a$ $sample$ $of$ $fewer$ $than$ $100$ $is$ $always$ $biased$
$No:$ $the$ $people$ $asked$ $know$ $the$ $most$ $about$ $it$

Show the worked steps

$The$ $people$ $were$ $chosen$ $at$ $random$ $from$ $the$ $whole$ $city.$
$No:$ $everyone$ $in$ $the$ $whole$ $city$ $had$ $the$ $same$ $chance$ $to$ $be$ $chosen$

Answer: $No:$ $everyone$ $in$ $the$ $whole$ $city$ $had$ $the$ $same$ $chance$ $to$ $be$ $chosen$

Textbook	Lessons
Glencoe Algebra 1	12-1, 12-2
Holt McDougal Larson Algebra 1	10.1
Math Nation Algebra 1 (Florida B.E.S.T.)	12.6
Pearson Algebra 1 Common Core	12-5
Reveal Algebra 1	12-3