Mathematics - 4 October 2006

I know that the formula is E(X^2)-[E(X)]^2
But I seem ot be getting the wrong answer?
X= 1,2,2,4,5
Pr(X=x)= 0.35,0.3,0.1,0.2,0.05 (respectivly)
Find the variance.
Can you please show working out. Thanks

2006-10-04 23:30:51 · 2 answers · asked by Anonymous

....what hope is there for the remaining 50%?

2006-10-04 23:27:06 · 13 answers · asked by Anonymous

In a couple of weeks we will once again go through the ritual of putting the clocks back 1 hour. A key initial premise for this was that children were in greater danger of being involved in an accident travelling to school in the morning darkness. However I believe there may be statistics which show that more accidents involving schoolchildren happen at dusk which now comes earlier as a result of the clocks going back. In addition, with more and more children being ferried to and from school by car the case for putting the clock back has all but vanished. Personally I think it would be better to have the one hour's extra daylight in the early evening. What do others think? Are we stuck with 'tradition'? What arguments can be marshalled in favour of not putting the clocks back?

2006-10-04 23:22:48 · 11 answers · asked by phil_intime 1

A limit point is a point at which a subsequence of the sequence converges.

2006-10-04 22:37:07 · 3 answers · asked by Nick 2

2006-10-04 21:59:27 · 11 answers · asked by asker 1

Low temperature at the night in a city is 1/3 more than 1/2 high as higher temperature in a day. Sum of the low temperature and highest temp. is 100 degrees. Then what is the low temp

provide me with steps..

2006-10-04 21:49:34 · 8 answers · asked by yamuna s 1

2006-10-04 21:47:03 · 1 answers · asked by glayse 2

for Rs. 100000 for 1 year interest rate is 12%
then how much will be the compound interest after 5 years ?
please also give the monthly compound interest rate calculation
how much do i get monthly interest for the 5 years.?

2006-10-04 21:45:36 · 8 answers · asked by harish s 1

call a maths class "Math" - what's wrong with the 's'?

2006-10-04 20:44:40 · 30 answers · asked by Phlodgeybodge 5

is there a mathematical equation to hand that can work out when in life i can expect to get my girlfriend? i am 35

2006-10-04 20:28:44 · 40 answers · asked by Anonymous

2006-10-04 20:27:49 · 13 answers · asked by bheem 1

(1-1/2) (1-1/4) (1-1/8) ... (1-1/2^n) ...

2006-10-04 20:12:10 · 7 answers · asked by Payam Samidoost 2

I just divided them into each other to equal 118X bigger but that doesn't sound right.

2006-10-04 19:44:25 · 3 answers · asked by THATgirl 6

please show your solution. tnx.

2006-10-04 19:19:47 · 7 answers · asked by chalkey 1

The number 384 in decimal system is given by (1234) x in the X System of numbers find the value of X

2006-10-04 19:05:15 · 8 answers · asked by yamuna s 1

please show your solution. tnx a lot.

2006-10-04 19:00:02 · 10 answers · asked by chalkey 1

2006-10-04 18:56:20 · 14 answers · asked by abdullabilavinakath 1

2006-10-04 18:54:42 · 10 answers · asked by Revan M 1

2006-10-04 18:49:36 · 5 answers · asked by chalkey 1

okay so im sure no one will help, it is a long problem. BUT just in case.

how can i solve this determinants problem:

2 32 1 4
26 104 26 -13
2 56 2 7
1 40 1 5

the answer is 45. I have no clue where to begin!! if anyone can at least help me start i would be more than grateful


THANKS!!!!!!!!!!!

2006-10-04 18:31:26 · 3 answers · asked by dvl_n_dskyz 3

A can copy 50 papers in 10 hours while both A & B can copy 70 papers in 10 hours. Then for how many hours required for B to copy 26 papers

2006-10-04 18:28:51 · 6 answers · asked by yamuna s 1

still suck in this problem
consider a rectangular box with a square base and surface area of 216 square inches. let x represent the length of each side base and h represent the height of the box
c. if the surface area is 216square inch ..express the variable h in term of x?
d. find the volume of box in term of x alone ?
(-_-) .. i kinda forgot all the Formulas ... plz help me again .. thank so much

2006-10-04 18:20:13 · 4 answers · asked by none 1

in detroit the tempature is 69degrees F and is rising at a rate of 2 degrees F per hour. In atlanta the tempatureis 84 degrees F and is falling at a rate of 3 degrees F per hour. If the temptaure continues to change at the same time rates, how long will it be before the tempatures are the same?

1. write a verbal model for this problem
2. write an equation for this model.
3 solve the equation and answer the question.

2006-10-04 18:06:48 · 7 answers · asked by NABEELiOS 1

you are desigining a house with 3-feet-wide windows on the back of the house. there are 3 windows and are 4 feet between each end window and an edge of the house. the width of the house is 33 feet. how far apart should the windows be?

1.write a verbal model
2. write an equation for the model
3. solve equation and answer question.

2006-10-04 17:52:56 · 3 answers · asked by NABEELiOS 1

you are desigining a house with 3-feet-wide windows on the back of the house. There are 4 feet between each end window and an edge ofthe house. the width of the house is 33 feet. how far apart should the windows be?

1.write a verbal model
2. write an equation for the model
3. solve equation and answer question.

2006-10-04 17:46:53 · 4 answers · asked by NABEELiOS 1

what is the absolute value of |-7| , |-2.9| ,
-|9+2| ?

2006-10-04 17:27:13 · 10 answers · asked by NABEELiOS 1

9x^2 + 12xy + 4y^2 - 25

2006-10-04 17:25:52 · 4 answers · asked by Samantha F 1

If the sides of a square are decreased by 2 cm, the area is decreased by
36 cm2. What were the dimensions of the original square?
show the work so I can learn it please. I am so confused

2006-10-04 17:24:10 · 6 answers · asked by Samantha F 1

4x^2=13x+12

2006-10-04 17:06:56 · 8 answers · asked by Samantha F 1

What's the answers to 3 1/4 - 1 5/8? 15 1/3- 6 1/2? 12 2/5- 4 3/4? And 12 5/8-3 3/4? Thanx I will appreciate it very much.

2006-10-04 17:01:28 · 6 answers · asked by Anonymous