Statıstıcs Iı

Yanıt Açıklaması: Q=1-P Q=1-0.40 Q=0.60

Yanıt Açıklaması: C.D.= r^2= 0.45^2=0.2025

Yanıt Açıklaması: If we know the proportion P for one class, the proportion of Q for the other class must be equal to 1 – P. Because the total probability must be equal to 1 and there are only two possible outcomes. For example, if the proportion of married people in a group is P = 0.63 then the proportion of the single in that group is Q=1-P = 1- 0.63 = 0.37. The correct answer is C.

Yanıt Açıklaması: In a paper in 1951, Leonard Hurwicz suggested a new method that balances the optimism and pessimism of the decision maker. In this method, the decision maker is allowed to have best and worst possible outcomes considered. In order to achieve this, Hurwicz suggests the use of coefficient of optimism. It is symbolized with ? and it is a decimal number between 0 and 1. If ? = 1, then the decision maker is hundred percent optimistic. If ? = 0, then the decision maker is hundred percent pessimistic. Since ? is the level of optimism we may easily call 1 – ? as the level of pessimism in the decision problem. Therefore, by changing the value of the ?, the decision maker may try to balance the optimism and pessimism.

Yanıt Açıklaması: (0.45)^2=0.2025

Yanıt Açıklaması: x = 15 . 0.6 + 12 (1 – 0.6) = 9 + 4.8 = 13.8 . pg. 194 . Correct answer is C.

Yanıt Açıklaması: Fisher's index = (Laspeyres' index . Paashe's index) 1/2 ; for this case : Laspeyres' inden . Paashe's index = Fisher's index ; x = ((40 . 8) / (60 . 7)) . 100 = (320 / 420) . 100 = 1600 / 21

Yanıt Açıklaması: Laspeyres Index was created by the German economist Étienne Laspeyres. The technique designed by Laspeyres uses base-period weights. It consists of the information about the price and quantity of products in different periods. The weighting scheme makes it a better tool than simple indexes. By using the Laspeyres index, it is possible to make a comparison of today’s price and quantity between the price and quantity of items altogether for a base period. The Laspeyres price index is also known as the average of weighted relative prices since it is a composite index number of prices formed by the weighted sum method. The index is found by the ratio of the sum of prices in the current period to the sum of the prices in the base period, these sums are weighted by the respective quantities of the base period. In this case, the weights which are used are the quantities of each commodity in the base period. So, it measures the relative price change of the commodities when the respective quantities are considered unchanged. The correct answer is B.

Yanıt Açıklaması: x = 2 . 0.25 + 4 . 0.75 = 0.50 + 3 = 3.5 . pg. 197 . Correct answer is D.

Yanıt Açıklaması: Using the equation the result is 0.267

Yanıt Açıklaması: As the number gets closer to 1, the correlation is stronger. Therefore if it is 1, it is perfect correlation and if it is 0, there is no correlation. In this example, correlation is almost 1, therefore it shows a very strong correlation. The correct answer is B.

Yanıt Açıklaması:

Yanıt Açıklaması: x = ((15 . 8) / (25 . 6)) . 100 = (120 / 150) . 100 = 80

Yanıt Açıklaması: E(S)=(45*(45+40+1))/2=1935

Yanıt Açıklaması: x = 80 . 0.6 + 30 . 04 = 48 + 12 = 60 . pg. 197 . Correct answer is B.

Yanıt Açıklaması: The parametric independent samples t test is based on several assumptions: two samples are independent of each other, the populations in the investigation for t test are normally distributed, and two populations that these two samples are taken from has the same variability. The Wilcoxon rank sum test is a non- parametric alternative test that involves less assumptions. Especially it does not require that our two populations have a specific known distribution. As long as the populations in question are independent and has the same variability, you may use Wilcoxon Rank Sum test. Therefore, if you want to know if two samples come from independent populations, this method is a good choice. Wilcoxon rank sum test assumes that the two population distributions are identical, although they may differ in location parameter, such as one distribution may be shifted to the right or to the left of the other distribution.

Yanıt Açıklaması: An additional important concept in statistical hypothesis testing is the power of the statistical test. The power of a statistical test is defined as the probability of rejecting the null hypothesis (H0 ) when the alternative hypothesis is actually true. Therefore, it could be inferred as the probability of correctly rejecting a null hypothesis (H0 ) when it is actually false. Then the power of a statistical test can be calculated as 1– β.

Yanıt Açıklaması: The method of finding the degree of relationship between the variables is called correlation analysis.

Yanıt Açıklaması: x = 1 – 0.34 = 0.66 . pg. 194 . Correct answer is C.

Yanıt Açıklaması: through a hypothesis-testing, it is also important to consider the probability of a type II error, failing to reject the null hypothesis (H0) when it is false, which is denoted by β. Then the type II error probability is, β = P(type I error) = P(fail to reject the null hypothesis H0 when it is actually false)