shrikant1986
New member
- Joined
- Oct 29, 2013
- Messages
- 1
A company researches in a new treatment. To test the treatment method the company
carries out a number of independent experiments, which follow a Bernoulli distribution. The
probability of success is 0.6. Over two days the experiments is completed with 40 experiment
on day 1 and 40 experiment on day 2. X1 is the number of successes on day 1 and X2 is the
number of successes on day 2. Y is at stochastic variabel so that Y = X1 + X2.
1. What is the distribution of Y? What is the mean and variance of Y?
2. What is the probability of getting more than 40 successes?
Assume that on the two days there are 40 successes.
3. Calculate the probability so there are 20 successes on the rst day and 20 successes on
the second day.
Insted of having a xed number of experiments the company want to tests until it
has 30 successes. Let Z be the number of trials that are required to achieve the 30
successes.
4. What is the distribution of Z? Make a graph of the function. What is the mean, the
median and maximum? (Notes that the median can be calculatet for a dicrete stochastic
variabel. In this case the median, x0:5 is de ne as P(X x0:5) 0:5 and P(X x0:5)
0:5)
carries out a number of independent experiments, which follow a Bernoulli distribution. The
probability of success is 0.6. Over two days the experiments is completed with 40 experiment
on day 1 and 40 experiment on day 2. X1 is the number of successes on day 1 and X2 is the
number of successes on day 2. Y is at stochastic variabel so that Y = X1 + X2.
1. What is the distribution of Y? What is the mean and variance of Y?
2. What is the probability of getting more than 40 successes?
Assume that on the two days there are 40 successes.
3. Calculate the probability so there are 20 successes on the rst day and 20 successes on
the second day.
Insted of having a xed number of experiments the company want to tests until it
has 30 successes. Let Z be the number of trials that are required to achieve the 30
successes.
4. What is the distribution of Z? Make a graph of the function. What is the mean, the
median and maximum? (Notes that the median can be calculatet for a dicrete stochastic
variabel. In this case the median, x0:5 is de ne as P(X x0:5) 0:5 and P(X x0:5)
0:5)