Question

medal and fan

Answer 1

Jorge wants to find the most popular way for teens to volunteer in the community. He cannot decide between two methods.

Option 1: He will ask every fifth person on each English class roster.
Option 2: He will attend a walkathon to ask teen participants about the ways they volunteer.

Which statement about the methods is true?
Option 1 is biased.
Option 2 is biased.
Neither is biased.
Both are biased.

Answer 2

what are your thoughts on this @Tizzle ?

Answer 3

i feel they are both biased

Answer 4

why is that?

Answer 5

because jorge is asking in two specific locations

Answer 6

actually maybe option one is not biased

Answer 7

option 1 could be done better to include more people, but it's actually not biased at all.

This is considered systematic sampling

Answer 8

so B?

Answer 9

option 2 is definitely biased

why? because the people at the walkathon are volunteering for the walkathon. These people probably have done it before and will do it again. Yes there will be some who won't do it again but it's probably a small number since it's purely voluntary. So it's essentially an echo chamber. If option 2 is done, then the results of the survey will be very skewed to imply that people mostly volunteer at the walkathon. The actual results may be more towards another type of charity or no charity at all

Answer 10

yeah thats what i figured the only thing that really threw me off was that he was asking in a English classroom

Answer 11

this is like going to a steakhouse bbq restaurant and asking the people there "are you a vegetarian?"

the answer is most likely "no" and that would lead the researchers to conclude that barely anyone is a vegetarian

Answer 12

yeah yeah, soo this one

Ariel wants to find out the most popular theme for spirit week at school. She cannot decide between two methods.

Option 1: She will poll each student who leaves the gym after sports practice.
Option 2: She will randomly poll three students from each first-period class.

Which statement about the methods is true?
Option 1 is biased.
Option 2 is biased.
Neither is biased.
Both are biased.

would be that neither are biased correct?

Answer 13

because neither are asking a question like the sort

Answer 14

option 1 isn't too bad, but there's a bit of bias since she's only asking the students who participate in sports. She's leaving out a lot of people

option 2 is the more unbiased option

Answer 15

so should i choose "Option 1 is biased" ?

Answer 16

yeah it's biased since it leaves out any non-sports people

Answer 17

would you like me to start another thread or whatever so you can get more medals?

Answer 18

the sports people will probably pick a sports theme for spirit week when the true popular theme may involve something completely different

Answer 19

ideally you should post one problem per thread to avoid clutter and lag, but that's only if the problem is very long and involves a lot of drawings or something

Answer 20

oh okay

Answer 21

Sofia is a helper for the kindergarten class and is in charge of picking a video for their end-of-year party. To choose which type of movie they would like best, she decided to survey every other child entering a matinee for a cartoon called, “Three Pretty Princesses.” The total number of children surveyed was 40. What is wrong with the way she selected her sample? Check all that apply.
The sample of 40 children is too small to represent all kindergartners.
The sample was taken at a specific movie, which will skew data towards that type of movie.
The sample is likely to include a lot more girls than boys, since the movie title is “Three Pretty Princesses.”
The sample should include the adults with the children instead of only children.
The sample should include the other peer helpers in her grade to include a greater age range.

should i make a new one for this?

Answer 22

it doesn't matter I guess. Tell me your thoughts on this one

Answer 23

i was thinking B and C only maybe even E

Answer 24

The sample was taken at a specific movie, which will skew data towards that type of movie.
The sample is likely to include a lot more girls than boys, since the movie title is “Three Pretty Princesses.”
The sample should include the other peer helpers in her grade to include a greater age range.

Answer 25

yeah the results are skewed to that particular movie and it's likely that there are more girls than boys who watch the movie

Answer 26

no, this is for a kindergarten class. There's no need to ask adults or any older kids

Answer 27

when you narrow the population down this specifically, there's no need to go outside the box

it's like if you're developing a steak sauce, why would you ask vegetarians? You only need to ask steak lovers

Answer 28

so The sample was taken at a specific movie, which will skew data towards that type of movie.
The sample is likely to include a lot more girls than boys, since the movie title is “Three Pretty Princesses.”

is just perfect

Answer 29

yeah both of those are equally valid

Answer 30

Leo wants to determine the average number of texts middle school students send in a day. Since all middle school students are enrolled in history, he randomly surveyed 4 students from each of Mr. Barnes’s eighth-grade history classes. Ms. Lopez and Mrs. Frank also teach eighth-grade history. What should Leo do to ensure his sample is representative of all middle school students?
He should take the sample as is because he randomly surveyed students in each of Mr. Barnes’s classes.
He should also take a sample from Ms. Lopez’s and Mrs. Frank’s classes so that each student has the same chance of being chosen.
He should survey each of the other history classes. Only one grade is being surveyed by this method.
He should survey all the students in all the history classes to make sure he collects enough data.

Answer 31

im guessing C

Answer 32

@jim_thompson5910

Answer 33

@Aveline

Answer 34

hint: three of those options only focus on that particular school. One of the options goes outside the box and considers every school

Answer 35

Yeah C? am i not correct Jim?

Answer 36

@jim_thompson5910

Answer 37

`C) He should survey each of the other history classes. Only one grade is being surveyed by this method.` only worries about that particular school but it doesn't consider other middle school students in other schools

Answer 38

So D because then he can ask all?

Answer 39

"He should survey all the students in all the history classes to make sure he collects enough data."

This includes college kids, elementary school kids, etc. It would not represent the middle-school population.
Also, surveying ALL the students in ALL history classes seems unrealistic.

Answer 40

good point, it's casting a wider net. A net that gets too wide

Answer 41

if it said "all of the other middle schools" then it would be better worded

Answer 42

so wait C is correcT?

Answer 43

yeah @Aveline makes a good point

Answer 44

Actually, I'm changing my answer lol :P

Answer 45

"He should also take a sample from Ms. Lopez’s and Mrs. Frank’s classes so that each student has the same chance of being chosen."

After rereading the question, I noticed this:
"all middle school students are enrolled in history"

Answer 46

C says that "only one grade is being surveyed by this method", so it wouldn't represent all middle-schoolers.

Answer 47

here's another way to fix choice D to make it a better suitable answer

He should survey all the students in all the middle school history classes to make sure he collects enough data

Answer 48

So can we all agree D? hahahahah

Answer 49

I'm going with B lol.
The answers could be more specific.

Answer 50

but "Ms. Lopez and Mrs. Frank also teach eighth-grade history"

Answer 51

Ok, now I'm torn between B and D.
D is too broad, but B is a bit too specific
...if jim says D, I'd go with D despite the fact that it is sooo broad.

Answer 52

yeah i agree its brain splitting

Answer 53

yeah the wording is too ambiguous

Answer 54

last question

Answer 55

i couldnt pick between B and D

Answer 56

Rule: the larger the IQR, the more variability you have

if you have a small IQR, then the box is very narrow and you have a better chance of picking the most representative data point

Answer 57

variability is also measured with the range or the standard deviation

Answer 58

Oh oh oh C!!!

Answer 59

yes

Answer 60

can i ask one more or...