1. Find the distribution of the said discrete CB X and its distribution function F (x). Calculate the expectation M (X), the variance of D (X) and standard deviation σ (X). Draw the graph of the distribution function F (x)

1.9. The probability of this exam for each of the four students is 0.8; SW X - the number of students who have passed the exam.

2. Dana distribution function F (x) DM X. Find the probability density function f (x), the expectation M (X), the variance of D (X), and the probability of hitting NE X on the interval [a; b]. Construct the graphs of the functions F (x) and f (x).

3. Solve the following problems.
3.9. Details issued shop, have diameters of, normally distributed with mean equal to 5 cm, and a variance equal to 0.81 cm2. Find the probability that the diameter taken at random parts - from 4 to 7 cm.

4. Solve the following problems.
4.9. What is necessary to make experiments with probability 0.9 to argue that the frequency of events of interest to us will be different from the probability of occurrence of this event, equal to 0.4, no more than 0.1?