Statıstıcs I Final 5. Deneme Sınavı

In order to avoid the disadvantages and misleading of the range and the IQR, we need a measure of variability that is based on including all measurements in a data set. The most important and widely used measure of variability in statistics is the standard deviation. To determine the variation of a data set in terms of the amounts, we need to measure the how much each observation deviates from the mean. The variability of a data set is small if the observations are close to their mean, and large if the observations are deviated widely about their mean. The correct answer is C. 

Probability of an Event = The number of times the event can happen / Total number of possible outcomes

P (more than 3) = 3 / 6 = 0,5

Normal distribution is one of the most significant and extensively used continuous probability
distribution. The major reason for this circumstance is majority of the continuous random variables
which are observed through real life applications (social, medical, physical, biological) are normally or
approximately normally distributed (bell-shaped) variables.

This probability is called Hypergeometric distribution.The correct answer is A.

Discrete random variables have only a countable number of separate values such as 0, 1, 2 , 3... etc. For example, the number of students in a class for certain day or the number of customers in a supermarket after 5:00 PM are cases for discrete random variables since these variables are finite and countable. Conversely, continuous random variable can take entire infinite values in a given interval. Because of this reason, continuous random variables are commonly measured instead of counted. For instance, waiting time for customers in a supermarket cashier line and travel time of a bus between two points are examples for continuous random variables. The correct answer is C.

z = (x – m) / sd ; sd = variance^1/2 ; (30 – 25) / 4 = 1.25 ; (35 – 25) / 4 = 2.5 ; P(1.25 <= z <= 2.5). pg. 200. Correct answer is E.

The range of a data set, shown as R, is the difference between the largest and smallest values and calculated as follows:

R = Largest Value - Smallest Value

Consider any two experiments of which the first experiment can result in n₁ and the second can result in n₂ possible outcomes. Then, considering both experiments together, there are n₁n₂ possible outcomes.

P=20x5=100

14 : occurs most often, it is repeated 5 times. pg. 77. Correct answer is A.

number of university students in Eskişehir. pg. 179. Correct answer is B.

In the classical probability approach to assign a probability to an event, the assumption is that all the outcomes have the same chance of happening. Pick up a six-sided fair die, there are six numbers on each face of the die as 1, 2, 3, 4, 5, and 6. Classical probability says that each side of the die has the same chance to come face up if this die is thrown. Since there are 6 possible outcomes of throwing a six-sided fair die probability of obtaining any number represented on the faces of this six-sided fair die is 1/6.

We have to compute P(x=0)+P(x=1)+P(x=2) in order to find the probability of at most 2 calls at a given minute.

P(x=0)=(e^-6*6⁰)/0!=0.00248

P(x=1)=(e^-6*6¹)/1!=0.0149   

P(x=2)=(e^-6*6²)/2!=0.0446

Thus P(x=0)+P(x=1)+P(x=2)=0.06198

P(A)=0.40  P(U/A)=0.10  P(U/A).P(A)=0.04

P(B)=0.35  P(U/B)=0.20  P(U/B).P(B)=0.07

P(C)=0.25  P(U/C)=0.05  P(U/C).P(C)=0.0125

P(U)=0,04+0,07+0,0125=0,12

The difference between 60(the highest) and 10(the lowest) is 50 so the correct answer is A