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

The null hypothesis always show the status quo. Therefore 

µ= 5000 is an example for the null hypothesis

In order find the point estimate

1000/4000=0.25.

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.

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. 

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. 

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

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.

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.

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

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. 

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

the difference is

45 - 80 = -35

F-test is used in such cases.

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

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

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. 

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

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.