Question

Identify the bias in each sample. a) A phone-in radio show asks callers their opinion about the city's baseball team not making the playoffs the day after they are eliminated. b) To learn which team Canadians feel will win the stanley cup, researchers call 100 people from ottawa. c) To find the age that most canadians feel should be the legal driiving age, researches ask 3000 high school students.

Answer 1

please help me someone : (

Answer 2

\[a) voluntary response bias b)inadequate sample size c) \]

Answer 3

c)..?

Answer 4

i didnt understand b ..!

Answer 5

meaning it's biased because it didn't adequately... ok. what I said was wrong. I think it is basically convenience sampling.

Answer 6

i guess your right

Answer 7

the third one is i think exactly the same reason.

Answer 8

so third one is convenience sampling too?

Answer 9

that's my guess

Answer 10

next question it says that . Sugeest a way to reduce the bias in each sample in this question

Answer 11

a) stratified random sampling b) stratified random sampling c) two stage cluster sampling

Answer 12

can i ask you a question?? what does bias mean .. like i dont get it

Answer 13

bias is like somebody is going to respond that way, ur data will be skewed, for example:

Answer 14

if u go to a rich neighborhood and ask them whether rich ppl should pay more taxes,

Answer 15

they will say NO, and if u go to a poor neighborhood and ask whether rich ppl should pay more taxes ppl are more likely to say yes... So both responses are biased

Answer 16

Basically u give a biased response if u get something sort of like profit from it..

Answer 17

o okay :) i get it

Answer 18

basically bias is when the sample mean is different from the true population mean

Answer 19

so why biased sample may not produce accurate results?

Answer 20

because you won't get accurate results..

Answer 21

because of methods you use

Answer 22

woops sorry lol, I meant because biased data is just like BSed data

Answer 23

ill let moo explain it lol I've never been good at stat.. Any calculus questions?

Answer 24

can u help me with statistic questions?

Answer 25

?? please"

Answer 26

i can try..

Answer 27

One way to judge the sucess of a movie is to rank it by ticket sales. however, tickets are more expensive today and theatres hold more people than in the past. suggest a way to remove these biases so that past and present movies can be compared fairly.

Answer 28

well the top option would be make the tickets cheap.

Answer 29

ok??

Answer 30

Not free, because then rich people would think that this movie is trash which is why they are giving away the tickets.. so you would only get responses from the rich

Answer 31

*sorry meant:
Not free, because then rich people would think that this movie is trash which is why they are giving away the tickets.. so you would only get responses from the poor people who would take the tickets

Answer 32

and if the ticket prices were high, then poor people wouldnt be able to afford them and you would get responses from only rich people

Answer 33

and to minimize bias you want responses from both rich and poor people, u need diversity

Answer 34

oh okk :)

Answer 35

can i ask next q?

Answer 36

sure..but i am pretty bad at stat if i can't do it then sorry..

Answer 37

sure :)

Answer 38

its just that my stat teacher was really bad, but i will attempt ur question

Answer 39

ok

Answer 40

a popular television sports show asked people to phone in their pick for the NBA Most Valuable player. with 30 min left in the show, they announce the result to that point. a) how might this announcement affect the outcome of the survey? b) Does reporting the early results make the survey biased? explain why or why not?

Answer 41

Okay first of all a) you will definitely get biased results, and you always want to avoid them.

Answer 42

b is easy

Answer 43

b) Reporting survey earlier would decrease the bias because look, it is the end of the game right, and suppose you were going to vote for player A, but turns out player B scored more goals or whatever u call em in basketball (sorry i hate american sports), so you will end up picking player B if you choose when there's 30 mins left..

Answer 44

And if you are reporting it early, then player A and B would have equal chances, because you don't know who is going to perform better..

Answer 45

ooo

Answer 46

do you kind of get it? If nothing affected your vote then it would NOT be biased, but halfway into the match, you see one guy is better than the other, so something is affecting your vote

Answer 47

next question is : Melissa asks five of her friends about their favourite type of movie. Four say their fav is comedy. She reports that 80% of teenagers prefer comedies over all other movie types. explain two flaws in her survey.

Answer 48

her sample size is too small..

Answer 49

or not sample size, i mean whatever you call it, you can't get sufficient data from only 5 people

Answer 50

okay it is called a sample size, just looked it up lol

Answer 51

lol

Answer 52

so now she should NOT have asked her friends who are each others' friends too, because most friends share common tastes, so they all would like comedies, or tragedies or whatever..

Answer 53

i mean friends tend to have same tastes don't they.. all of my friends like math lol ..well sorta..

Answer 54

yea right :P

Answer 55

any more?

Answer 56

A local soccer league wants to give its players a bonus: either free soccer balls, free movie tickets , ir coupons for the snack bar. a) Design a survey the league can use to decide which bounus to offer. b) how can the data be collected? c) is it possible to survey the whole population?? explain?

Answer 57

??

Answer 58

thinking..

Answer 59

ok

Answer 60

uhmm i dont get it what is the survey about? do we have to ask whether they want one of those options? either free soccer balls, free movie tickets , ir coupons for the snack bar?

Answer 61

yessss i gues we need to ask :S

Answer 62

well i guess for part A:
We could either mail them letters or something asking what they would prefer, or email them or call them, etc..
B:
Let soccer balls be 1
tickets - 2
coupons - 3, ask whichever they prefer and record the number then see how many counts of each number we have..

Answer 63

C:
It is never possible to interview the whole population, because some people will think its a scam and not respond, others will just think that its a joke or something and just respond with a random number without actually thinking about what they want..

Answer 64

post the next one..

Answer 65

explain the difference between response bias and non- response bias. b) are two biases opposites? explain. c) Giv an example of each.

Answer 66

THIS CALLS FOR SOME GOOGLINGG!! LOL afk.. lookin

Answer 67

hahaha :P man google dosnt make any sense :P coz i need to understand what it is :P lol

Answer 68

Non response bias is NOT the opposite of response bias.. that's as much as i know so far..

Answer 69

okay I know what a response bias is:
It occurs when the survey takers says something that he or she thinks the surveyor wants to hear from them.

Answer 70

For example:
A teacher asks the kids DID YOU DO YOUR HOMEWORK???
Kids will respond of course we did, because they think they will get punished otherwise..

Answer 71

that's response bias..

Answer 72

o

Answer 73

non response is basicaly oppsite of that .. right?

Answer 74

no its not

Answer 75

outch

Answer 76

so that's half of part a and c so far, let me understand what non response bias is..

Answer 77

Okay non response bias is basically when you don't respond

Answer 78

thats what i said lol

Answer 79

well u don't DON'T respond just because u think u will be punished or lose something..

Answer 80

is tht it?

Answer 81

no, imagine this

Answer 82

did u answer b ??

Answer 83

yeah thats b

Answer 84

they are not opposites..

Answer 85

c) Response bias:
teacher : "did u do ur hw?"
kids: "yes" even though maybe they didnt
Non- response bias:

Answer 86

Imagine a guy standing on the corner of Lexington ave and 23rd street in manhattan asking college kids rushing by whether they want to take a survey.. Most of them including me would say NO, simply because they don't have time..

Answer 87

Lex and 23rd is crazy.... especially durin breaks in b/n classes...=(

Answer 88

so that's C, now for A

Answer 89

u told me a already dude

Answer 90

oh okay.. =)

Answer 91

sorry im like helpin 3 ppl, hard to keep track... im such a nerd -_-...

Answer 92

i should be enjoying life, but here i am stuck helpin others, i think i should log off...

Answer 93

holy ship 92 replies? *this is 93rd..

Answer 94

heyy thankyouu soo much.. i was writing the answer :SS :) ur really halpful thanks a lot

Answer 95

ready to help with math only... maybe I should become a math teacher lol, I hate teaching and tutoring, but somehow im okay at it..