Statıstıcs Iı

Yanıt Açıklaması: Probability sampling methods are simple random sampling, stratified sampling, cluster sampling, and systematic sampling. The correct answer is B.

Yanıt Açıklaması: The null hypothesis always show the status quo. Therefore µ= 5000 is an example for the null hypothesis

Yanıt Açıklaması: In order find the point estimate 1000/4000=0.25.

Yanıt Açıklaması: Statistical hypothesis tests are used to make a decision about whether the null hypothesis should be accepted or rejected. Since these conclusions are based on sample data, there is a risk of incorrect decision. There are two types of incorrect decisions through hypothesis testing: type I error and type II error. Type I error is defined as rejecting the null hypothesis (H0 ) when it is actually true. On the other hand, Type II error is defined as failing to reject the null hypothesis (H0 ) when it is actually false.

Yanıt Açıklaması: The null hypothesis (H0 ) and alternative hypothesis (H1 ) for the mean yield rate of the produce can be expressed as follows; H0 : µ1 = µ2 = µ3. The correct answer is E.

Yanıt Açıklaması: Z test statistic can be used for difference between two means if sample sizes are greater than or equal to 30. The correct answer is E.

Yanıt Açıklaması: st err = st dev / (n) 1/2 = 36 / (9) 1/2 = 12 . pg. 38 Correct answer is A.

Yanıt Açıklaması: The null hypothesis H0 is a statistical statement which specifies that there is a specific value of a population parameter. Generally thought as the status quo. It is what you already know about the population parameter. The correct answer is A.

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. The correct answer is E.

Yanıt Açıklaması: In an investigation, if the confidence level is 0,95 ; the significance level of this study is 0,05. The correct answer is B.

Yanıt Açıklaması: For the right sided (upper tailed) test, the null hypothesis (H0 ) is in the following form: H0 : µ1 – µ2 = 0 The correct answer is A.

Yanıt Açıklaması: x = (42 + 45 + 47 + 54 + 58) / 5 = 49.2. pg. 24. Correct answer is C.

Yanıt Açıklaması: Probability sampling methods provide a statistical basis for saying that a sample is representative of the target population. In probability sampling methods, every unit of the target population have a known and non-zero probability of being selected for the sample. We can say that because probability sampling methods use a random mechanism thus eliminating subjectivity in the selection of a sample, these methods are an unbiased way of creating a sample.

Yanıt Açıklaması: the difference is 45 - 80 = -35

Yanıt Açıklaması: F-test is used in such cases.

Yanıt Açıklaması: If population variances are assumed to be equal then the degrees of freedom=m+n-2.

Yanıt Açıklaması: 28 + 1.96 * (12 / sqrt(16)) = 33.88

Yanıt Açıklaması: To test the claims made about the population parameters or in other words to test the statistical expressions the following steps can be followed: Step 1: State null and alternate hypotheses Step 2: Select a level of significance Step 3: Identify the test statistic Step 4: Formulate a decision rule Step 5: Take a sample and make the decision.

Yanıt Açıklaması: x = (99 + 123) / 2 = 111. pg. 33. Correct answer is B.

Yanıt Açıklaması: so t=(56-54)/ ? (1/10+2/20)=2/ ? 0.2=4.47. Degrees of freedom is 9 (since the smaller of 10-1 and 20-1 is 9) since the population variances are different. Thus the critical value of t=1.833. Since the calculated t is bigger than critical value we reject the null hypothesis that brand A and B have same weight. Thus we conclude that their weights differ at 0.05 significance level.