25 Aralık 2014 Perşembe

Examples

    Question 1
    A fair die is tossed 7 times. We say that a toss is a success if a 5 or 6 appears, otherwise it’s a failure. What is the distribution of the random variable. X representing the number of success out of the 7 tosses? What is the probability that there are exactly 3 success? What is the probobility that there are no success?

         n=7  p=1/3


   P(x=3)=(7/3).(1/3)^3.(2/3)^4=560/2187


   P(x=0)=(2/7)^7=128/2187
Question 2
       Bob is a high school basketball player. He is a 70% free throw shooter. That means his probability of making a free throw is 0.70. What is the probability that Bob makes his first free throw or his fifth shot? 
 
P.Q^(X-1)=0,7.(0,3)^4=0,00567
Questions 3


      Suppose that the amount of time one spends in a bank exponentially distributed with mean 10 minutes, N=1/10.  What is the probability than 15 minutes in the bank? What is the probability that a costumer will spend more than 15 minutes in the bank given he is still in the bank after 10 minutes?

 P(x>15)=e^(-15N)=e^(-3/2)

 P(x>15| x>10)=P(x>5)=e^(-1/2)=0.604

Question 4


    If electricity power foilures occur according to a Poisson distribution with an average of 3 failures every twenty weeks, calculate the probability that there will not be more than one failure during a particular week.

      —N:3/20=0,15

    Not more then one failure means we need to include the probabilities for “0 failuresplus “1 failure
P(x0)+P(x1)=(e^-0,15.0,15)/0! +                   (e^-0,18.0,15)/1! = 0,98981 
 
   
Question 5

   
    We report the dice tossing experiment described. We ask that is the probability that the die will land on a number that is smaller than 4?

P(x<5)=P(x=1)+P(x=2)+P(X=4)= 1/6+1/6+1/6+1/6=2/3 
 Question 6



3 Aralık 2014 Çarşamba

14 Kasım 2014 Cuma

ASSIGNMENT QUESTION


We are examining birthdays of 30 people. What is the probability
 that no one’s birthday is on the same day? What is the 
probability that at least two people’s birthday is on the same 
day?

 
and





15 Ekim 2014 Çarşamba

CALCULATING FREQUENCY

  How much money do you spent for transportation monthly?

We asked everyone

There are total numbers and frequency. For example six people spends fifty liras for transportation , sexteen people spends eighty liras..
 
There are relative frequency and cumulative frequency.

 HISTOGRAM


 

This is histogram. There is numbers of frequency on the y axis and there is number of relative frequency on the x axis.