Statıstıcs Iı

Yanıt Açıklaması: The degrees of freedom is,    d.f = n – 1 = 15 – 1 = 14.  The correct answer is C.

Yanıt Açıklaması: The formula gives the test statistic for two sample tests of means when their population variances are known. since x1 - x2 =3, and the denominator of the formula can be written as {[(2) 2 /100]+[(5) 2 /500]} 1/2 which would be equal to 0.3. This would yield to z=3/(0.3) = 10 The answer is A

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Yanıt Açıklaması: For two sided (two tailed) test, the null hypothesis (H 0 ) and the alternative hypothesis (H 1 ) are in the following form, H 0 : µ 1 – µ 2 = 0 H 1 : µ 1 – µ 2 ≠ 0 This hypothesis equivalently can be expressed as, H 0 : µ 1 = µ 2 (There is no difference) H 1 : µ 1 ≠ µ 2 (There is a difference) The answer is A.

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 (H 0 ) 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 H 0 when it is actually false) The answer is B.

Yanıt Açıklaması: The last sample observation (4th observation) is found at the value of 18. The numbers bigger than 40 are disregarded therefore the answer is 18.

Yanıt Açıklaması: x = (4.4 + 5.6 + 4.5 + 5.5) /4 = 5. pg. 24. Correct answer is C.

Yanıt Açıklaması: Variance=p*(1-p)=0.1*0.9=0.09

Yanıt Açıklaması: For the one-way ANOVA test, the test statistic is the ratio of two variances: namely the variance between samples and the variance within samples. The correct answer is D.

Yanıt Açıklaması: Convenience Sampling A convenience sample involves a group of individuals that is ready and available. It is also called availability sampling method. A convenience sampling is used to create sample as per ease of access, readiness to be a part of the sample, availability at a given time period or any other specifications of a particular element. The surveyors select members merely on the basis of proximity and does not consider whether they represent the entire population or not. By using this sampling techniques, we can observe habits, opinions, and viewpoints in the easiest possible manner. Many researchers prefer convenience sampling method because it is inexpensive, easy and applied quickly. Because of the potential for bias in the sampling method, the results obtained from this sampling method should be reported and used with a great caution.

Yanıt Açıklaması: For the left sided (lower tailed) test, the null hypothesis (H0) and the alternative hypothesis (H1) are in the following form, H0: µ1 – µ2 = 0 H1: µ1 – µ2 < 0 This hypothesis equivalently can be expressed as, H0: µ1 = µ2 H1: µ1 < µ2

Yanıt Açıklaması: Every statistical hypothesis-testing process begins with the statement of a hypothesis. There are two types of statistical hypotheses for each circumstance. These hypotheses are the null hypothesis and the alternative hypothesis which are denoted by H0 and H1 respectively.

Yanıt Açıklaması: x = 72 / 180 = 0.40. pg. 25. Correct answer is C.

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Yanıt Açıklaması: An extension of cluster sampling in which clusters are selected and a sample is drawn from the cluster members by simple random sampling is called multistage sampling. pg. 12. Correct answer is B.

Yanıt Açıklaması: For the F test procedure, the sample sizes do not need to be equal.The F (one-way ANOVA) test to compare more than two population means is always a right tailed test. If F test statistic value is greater than 1, the null hypothesis should be rejected. Therefore, the correct answer is B.

Yanıt Açıklaması: In stratified sampling method, the target population is divided into homogenous subgroups which are called strata?

Yanıt Açıklaması: It will be equal to the population arithmetic mean and the population arithmetic mean in this problem is 50.