Question

@ganeshie8

Answer 1

like this one

Answer 2

Notice that July is left skewed, and the August is right skeewed

Answer 3

we dont know how many observations are outliers

Answer 4

so there is no way to tell which mean would be higher

Answer 5

right so there's no way to tell the mean?

Answer 6

oh haha

Answer 7

yep, pick the last option and try ur luck :)

Answer 8

after u submit, do let me knw what the grader says,...

Answer 9

Could you help me with a few more?

Answer 10

will do :)

Answer 11

yeah sure

Answer 12

check for outliers in Rome and Newyork

Answer 13

here is the rule :
if you have outliers, then use median
if you dont have outliers, then use mean

Answer 14

A?

Answer 15

Rome has no outliers => mean
Newyork has outliers => median

Answer 16

C

Answer 17

wait but isnt the minimum in rome an outlier?

Answer 18

or not..idk what i was thinking

Answer 19

Range for Rome in box plot :
\((3 -1.5*10,~ 13+1.5*10) = (-12, ~28)\)

Answer 20

ahhh -12...i was getting 12

Answer 21

since the minimum and maximum \((0, ~16)\) lies within \((-12, ~28)\),
there are no outliers in Rome

Answer 22

i see...i have 2 more...?

Answer 23

sure

Answer 24

what is standard deviation?

Answer 25

its a quantity that measures the amount of spread

Answer 26

i see no outliers in both box plots
so i would use standard deviation for both

Answer 27

but i could be wrong on this one...
next question ?

Answer 28

im still confused
if standard dev. means the spread and theyre asking for spread, wouldnt it be standard dev?

Answer 29

here is the rule :

outliers => use median/IQR
no ouliers => use mean/standard deviation

Answer 30

both `IQR` and `standard deviation` quantify the amount of spread in a dataset

Answer 31

but you need to use `stadard deviation` as you dont have any outliers

Answer 32

but the bb game has an outlier causing the skew..no?

Answer 33

wouldnt it?

Answer 34

its slightly skewed, but there are no outliers

Answer 35

so neither has outliers therefore its D?

Answer 36

http://web.anglia.ac.uk/numbers/common_folder/graphics/fig6_single_box.jpg

Answer 37

Yep !

Answer 38

last one! @ganeshie8

Answer 39

i know B and C are wrong

Answer 40

i just cant decide whether its A or D since they both sorta make sense

Answer 41

i think its B

Answer 42

okay wait the females has an outlier but the males doesnt

Answer 43

i think ur box plots are not showing outliers separately
so the skewed males can have outliers

Answer 44

im super confused about this last one

Answer 45

yeah usually the boxplots need to show dots to indicate outliers,
but ur plots are not showing the outliers separately

Answer 46

So that means the males have a significant outlier as the plot is skewed to right

Answer 47

if you do 1.5(24)+25 it gives the upper range to be 61 so there arent any outliers

Answer 48

yep i see your point :) look at below correct problem :
http://prntscr.com/3irbtz

Answer 49

yea and the outlier follows the outlier test on that problem

Answer 50

what test ?

Answer 51

15-1.5(21-15)=9 so the lower range is 6 thats why theres an outlier on the problem you showed me

Answer 52

lower range is 9*

Answer 53

oh yes you're right :

Q1 = 15
IQR = 5

left boundary = 15 - 1.5*5 > 0


so there are outliers

Answer 54

one sec, leme work the present problem again :)

Answer 55

okay

Answer 56

does A make sense?

Answer 57

A makes perfect sense ! and yes you're right both plots have any outliers

Answer 58

so the earlier discussion on question#7 is incorrect

Answer 59

so what would it be for 7?

Answer 60

http://assets.openstudy.com/updates/attachments/5371a11ee4b0c9ccedc723b7-yummydum-1399956915335-7.png

Answer 61

Movies : No outliers => standard deviation
Games : outliers => IQR

Answer 62

it has to be B

Answer 63

so it is B

Answer 64

yes

Answer 65

okay now what about 4?

Answer 66

we concluded right, the females worked less

Answer 67

so A?

Answer 68

oh you're gona ask why its not D

Answer 69

sure, why isnt it D? :)

Answer 70

lol idk both A and D are true about the shown box plots

Answer 71

but the question is not asking "which of the below options are true"

Answer 72

its asking which of the below "affect the spread and center"

Answer 73

right it asked about affect

Answer 74

I'd go wid A - i feel it -_-

Answer 75

You did good :) it'll be an A i hope

Answer 76

stats is probably the toughest topic in alg1/2 i guess... good luck wid the test !

Answer 77

no kidding haha, thanks

Answer 78

when data is skewed in a box plot do you use mean or median?

Answer 79

median,
one sec i have a nice table showing when to use mean/median/IQR/standard deviations