TEST 1									
							Measures of central tendency		
1) Determine the following values:							Mean:		
	1	2	2	3					
	1	2	2	3			Mode:		
	1	2	2	3					
	1	2	2	4			Median:		
	1	2	2	4					
	1	2	2	4			Measures of variability		
	1	2	2	4			Sample variance		
	1	2	2	4					
	1	2	2	4			Sample Standard deviation		
	1	2	3	4					
	1	2	3	4			Range		
	1	2	3	4					
	1	2	3	4			Variation coefficient		
	1	2	3	4					
									
2) Determine the average number of computers in households:									
									
number of computers	0	1	2	3					
number of households	6	10	15	5					
									
									
3) How many ways can two students be selected from a group of 6 students?									
4) If each value from random sample were tripled then its variance is:	nine times higher comparing to original one	three times higher comparing to original one	twice higher comparing to original one	the same					
									
5) Complete the following rules:				ANSWER (choose a)b)c)d))					
"A)Addition Rule: P(A ∪ B) =…..., where A and B are events."			a) ... = P(A) ⋅ P(B)	A)					
B)Complementary Rule: P(A') = ……... denotes the probability of an event not happening.			b) ... = P(A) + P(B) - P(A∩B)	B)					
C)Independent events: P(A∩B) = …………			c) … = 1 - P(A). P(A')	C)					
D)Conditional probability: P(A | B) = ………..			d) … = P(A∩B) / P(B)	D)					
									
									
6) There are 5 green 7 red balls. Two balls are selected one by one without replacement. Find the probability that first is green and second is red.									
									
7) What is the probability of getting a sum of 8 when two dice are thrown?									
									
8)									
The number of days on business trip	Probability								
0	0.2								
1	0.3								
2	0.2								
3									
4	0.1								
									
"Fill in the missing value. Calculate mean, variance, mode, median."									
									
									
9)  The probability of success (hitting the basket) is 0.8. We have 5 attempts.									
What is the probability of hitting the basket:									
a) just 4x?									
									
									
b) maxium 4x?									
									
									
c) less than 2x?									
									
E(X)=									
D(X)=									
									
10) The number of telephone connections to the rescue system is an average of 4 calls per 20 minutes.									
a) What is the probability that the system receives 8 calls in 30 minutes?									
									
									
									
b) no more than 7 calls per hour?									
									
									
c) at least 1 call per 40 minutes?									
									
									
E(X)=									
D(X)=