S1 and S2 DOUBTS HERE!!!!

[narnia]

a fair dice is thrown once. what is the probability that the score is greatr than 3 or a prime number or both?
i added 3/6 + 3/6 + ( 3/6*3/6) , my ans being 5/4 wherews ans given is 5/6 =s

[EMO123]

a fair dice is thrown once. what is the probability that the score is greatr than 3 or a prime number or both?
i added 3/6 + 3/6 + ( 3/6*3/6) , my ans being 5/4 wherews ans given is 5/6 =s

(x>3)=4,5,6
p of (x>3)=3/6
(x a prime number)= 2,3,5,   
p of (x a prime number)
So both =2,3,5 and 4,5,6

5 is repeated so (2,3,4,5,6)=p of both 5/6
the Question was to confuse you .

[ashish]

rex has an old car. the probability that he is able to start the car on a rainy day is 0.2 and the probability that he is able to start it on a fine day is 0.6 . if the weather is either fine or rainy, and probability the weather is fine is p, the find in terms of p
1) the probability that he is unable to start the car on a day
2) the conditional probability that a day is fine and he is unable to start the car?

can someone solve this question please

[astarmathsandphysics]

One mo

[astarmathsandphysics]

prob solved in attachment

[EMO123]

prob solved in attachment

thanx Mr. Paul

[astarmathsandphysics]

No probs

[Malak]

Need help with this question

Part (e) to find median
I know we use interpolation but i am confused with the values to use for the upper/lower cumulative frequency..
thx

This is S1 Q5 from 2007 Jun

[mdwael]

Need help with this question

Part (e) to find median
I know we use interpolation but i am confused with the values to use for the upper/lower cumulative frequency..
thx

This is S1 Q5 from 2007 Jun

First of all make a cumulative frequency table.

you have a total of 100. Thus median should be the 50th entry.. so when you make the cf you will find the the 50th tab lies in 14-18 class and Cf is 26-50.. here it is not neccessary to do interpolation because 50 is the last one in the class so you can directly pick median of t is 18 seconds. but you can still do interpolation to check your answer.


    (X - 14) / 18-14 = 50-26 / 50 -26

X-14 / 4 = 1

X-14 = 4

X = 14 + 4 = 18


In the same manner u find the quartiles... since the  total frequency is 100 so lower quartile is 100/4 = 25 and upper is 100*3/4 = 75th entry

[mdwael]

I have a question regarding Normal Distribution..

I understand how to get and find probabilities but how do you find the mean and standard deviation when the lower quartile and upper quaritle are given? like in this question..

[Aadeez || Zafar]

in normal distribution,
median =means

and so median= (LQ+UQ)/2

using mean value find s.d

[Arthur Bon Zavi]

in normal distribution,
median =means

and so median= (LQ+UQ)/2

using mean value find s.d

BOLD - How can this be possible ?

Take upper quartile as 75 % (probability of 0.75) OR lower quartile as 25 % (probability of 0.25). Though I recommend you to take 0.75 because for LOWER QUARTILE (0.25) you have to do a bit of more subtraction which will be confusing.

[xMilishax]

Can someone help me solve:
May 2010 Q7 Part (b)?

I'm kinda confused with Normal distribution.

Thanks. 

[Arthur Bon Zavi]

Can someone help me solve:
May 2010 Q7 Part (b)?

I'm kinda confused with Normal distribution.

Thanks. 

Variant ?

[xMilishax]

Variant ?

Variant 1