AnswersCR02201A Probability and StatisticsPopulations and Sampling

Sampling Methods Answers

10 verified answers
1
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Chelsea wants to determine the number of people in her school who read news reports on the Internet daily. She asks five people in her language arts class. Which improvements could Chelsea make to her sample to increase the validity of the results? Select three options.

A
increase the sample size
B
choose students from different grade levels
C
choose every fourth student in all language arts classes
D
decrease the sample size
E
choose students whose answer to the survey question is predetermined
2
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most

5
50 students in the art club
4
40 girls on her soccer team
2
2 students from each of the 15 classes
1
10 students from each of the 3 computer electives
3

most

T
The representative sample contained all 200 tourists.
T
The representative sample contained more adults than children.
T
The representative sample contained more children than adults.
T
The representative sample contained an equal number of adults and children.
4

best

M
Michelle’s because she sampled the saplings of every family in her group
M
Michelle’s because she sampled the saplings of the first 20 families to choose their saplings
A
Ari’s because she sampled saplings chosen at different times
A
Ari’s because she sampled one more sapling than Michelle sampled
5

best

N
Nathan’s because his sample was more random
J
Jordan’s because his sample was more random
N
Nathan’s because his sample contained elements of the population
J
Jordan’s because his sample contained elements of the population
6

The chart below shows the distribution of weeds in a yard. A lawn-care specialist chooses a random sample from the yard and determines the number of weeds in the sample. The results of the sample are shown in the table below.Weed TypeNumberDandelion2Clover3Crab Grass2Chickweed2Which explains whether or not this is a representative sample?

Question illustration
Y
Yes, this is a representative sample because each type of weed is represented in the sample.
Y
Yes, this is a representative sample because each type of weed is represented approximately the same number of times in the sample.
N
No, this is not a representative sample because each type of weed should be represented in proportion to the number of weeds actually present in the yard.
N
No, this is not a representative sample because each type of weed should be represented exactly the same number of times in the sample.
7

best

T
The sample size is not large enough to represent the population.
T
The sample was not chosen at random.
T
The way the sample was chosen may overrepresent or underrepresent students taking certain language classes.
T
The way the sample was chosen does not sample students from each different language class.
8

The chart below shows the distribution of the number of books in a library.Sahira chooses a random sample from the library and records the type of books in the chart below.Type of BookNumberFantasy10Literature25Children’s4Nonfiction11Which explains whether or not Sahira’s sample is representative?

Question illustration
N
No, it is not representative because literature books were chosen much more often than the other types.
Y
Yes, it is representative because each type of book was chosen a unique number of times.
Y
Yes, it is representative because each type of book was represented in the approximate proportion that exists in the library.
Y
Yes, it is representative because each type of book was selected as part of the sample.
9

most

T
The representative sample contained all 160 students.
T
The representative sample contained more boys than girls.
T
The representative sample contained more girls than boys.
T
The representative sample contained an equal number of boys and girls.
10

best

r
random and biased
r
random and unbiased
n
nonrandom and biased
n
nonrandom and unbiased

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