Question

Stats help required

Answer 1

\[mean = \frac{\sum fx}{\sum x}\]

Answer 2

ah, so it's just a weighted average.

Answer 3

Solve the following for x:
\[\frac{12(x-5)+40x+8(x+5)}{60}=10\]

Answer 4

Whatt is the general formula @kropot72

Answer 5

\[\dfrac{\underbrace{x - 5 + x - 5 \cdots+ x-5}_{\rm 12 ~times} + \underbrace{x + x\cdots x + x}_{\rm 40 ~ times} + \underbrace{x + 5 +\cdots+ x+5}_{\rm 8 ~times}}{12 + 40 + 8}\]

Answer 6

Thanks a lot but there would be some general form of this :/

Answer 7

@Mimi_x3

Answer 8

I wrote the general formula already.

Answer 9

Shouldnt it be,

\[\sum_{}^{}fx/\sum_{}^{}f\]

Answer 10

Next.

Answer 11

\[Arithmetic => \frac{x+y}{2} = 10.2\]

Answer 12

What about geometric?

Answer 13

Geo mean formula: √(xy)

Answer 14

Sqrt(x*y)

Answer 15

Okay got it

Answer 16

\[√(xy) = 8.4\]

Answer 17

Do i have to solve quad equations?

Answer 18

take square on both sides:
xy = sqrt8.4

x = sqrt(8.4)/y

Answer 19

I know that

Answer 20

Now substitute this in the first equation

Answer 21

But it would be x=70.56/y

Answer 22

o_O

Answer 23

Whut?

Answer 24

sqrt(xy)=8.4

xy=70.56

x=70.56/y

Answer 25

Oh right.

Answer 26

Actually i'm doing two things at once. XD

Answer 27

No worries c:,This thing is going into a quad equation :(

Answer 28

Go for it

Answer 29

x=77.16,-56.76 and y=77.16,-56.76

Answer 30

I feel like i have made a mistake :/

Answer 31

Let me check.

Answer 32

Should i do it again?

Answer 33

x = 4.41, y = 15.99
x = 15.99, y = 4.41

Answer 34

Lemme do it again,Stop playing with wolf :/

Answer 35

may i help?

Answer 36

No thanks

Answer 37

ok do post your answer here

Answer 38

if you're completed with your soln

Answer 39

I will

Answer 40

Okay
x=15.98,4.414 and y=4.414,15.98

Answer 41

great.

Answer 42

Now next question,

I am getting b=2,b=8 and a=8,a=2

Answer 43

So harmonic mean is 16/5=3.2

Answer 44

Right @saifoo.khan ?

Answer 45

Never heard of harmonic mean. :s

Answer 46

Okay lets call someone else for that case,What about the observation do you think they are right?

Btw,A.M is opposite of H.M.

Answer 47

I cn help in HM

Answer 48

And,

H.M=N/(1/a1+1/a2+......1/an)

Answer 49

@mathslover Do you think my answers are correct?

Answer 50

lemme check tht .. wait

Answer 51

Okay

Answer 52

yep u r right

Answer 53

great work

Answer 54

Thanks but now i want to ask,

As i have two diff observations a=8,b=2 and a=2,b=8 and the HM is same so should i show this two times?

Answer 55

yes you have to mention that it will be same in both cases

Answer 56

Okay now next question.

Answer 57

Wait a sec

Answer 58

Namaz parhlo.

Answer 59

Chalo okay namaz kai baad krtai hai.

Answer 60

Han continue karlain @saifoo.khan

Answer 61

@AravindG Can you help?

Answer 62

sorry I am a really busy ...

Answer 63

I am really busy*

Answer 64

@saifoo.khan I am waiting :/

Answer 65

@hartnn Help pleaseeeeeeeeeeeeee

Answer 66

@hartnn

See the last attachment

Answer 67

same weighted average formula.

Answer 68

(700*8.5+800*7.5+500*8)/2000

Answer 69

\(\sum_{}^{}fx/\sum_{}^{}f\)

Answer 70

I was thinking about using this but i am not getting why is sum of f=2000

Answer 71

sum of f = 700+800+500

Answer 72

Okay thanks :)

Answer 73

I am getting mean=7.85,Am i right? @mathslover

Answer 74

@hartnn

Answer 75

7.975
https://www.google.co.in/search?q=(700*8.5%2B800*7.5%2B500*8)%2F2000&aq=f&oq=(700*8.5%2B800*7.5%2B500*8)%2F2000&aqs=chrome.0.57.460&sourceid=chrome&ie=UTF-8

Answer 76

Close enough lol :P

I am using a casio scientific calculator,I dont know why it rounded the answers :/

Answer 77

Oh yeah i checked it again,Its 7.95 thanks.

I have another question may i ask? @hartnn

Answer 78

yes

Answer 79

Okay here we go :D

Answer 80

you tried ?

Answer 81

Wait wait dont answer i am trying

Answer 82

\[\sum_{i=1}^{n}a_i=16.2\]


Okay @hartnn Please explain