Seçmeli Ara Sınav - Statıstıcs Iı

Soru 1:

Which one of the following is not a probability sampling method?

A) Simple random sampling B) Convenience sampling C) Stratified sampling D) Cluster sampling E) Systematic sampling

Soru 2:

Which of the following can be the null hypothesis?

A) µ= 5000 B) µ != 5000 C) µ > 5000 D) µ < 5000 E) µ <> 5000

Soru 3:

the government policy planner is selected 4000 people from the population using cluster sampling, clusters are organized according to the geographical regions. Then, planner is found that the 1000 people in the sample live under the poverty threshold. What is the point estimate of the population proportion?

A) 0.75 B) 0.25 C) 0.50 D) 0.15 E) 0.90

Soru 4:

There are two types of incorrect decisions through hypothesis testing. Which of the following describes " type I error" ?

A) rejecting the null hypothesis when it is actually true B) rejecting the alternate hypothesis when it is actually true C) failing to reject the null hypothesis when it is actually false D) failing to reject the alternate hypothesis when it is actually false E) rejecting the null and alternate hypotheses when they are actually true

Soru 5:

An agricultural engineer wants to determine whether there is a difference in the mean yield of three different agricultural ingredients to increase the mean yield of a certain produce in a decares. What is the null hypothesis?

A) H0 : µ1 ≠ µ2 ≠ µ3 B) H0 : µ1 ≠ µ2 = µ3 C) H0 : µ1≠ µ2 D) H0 : µ1 = µ2 E) H0 : µ1 = µ2 = µ3

Soru 6:

In order to use Z test statistic for difference between two means, what is the minimum required sample size?

A) 10 B) 15 C) 20 D) 25 E) 30

Soru 7:

Interval estimation problem : the population standard deviation is not known, the sample standard deviation is 36, there are 9 observations in the sample. What is the value of the standard error to calculate the confidence interval?

A) 12 B) 9 C) 6 D) 4 E) 2

Soru 8:

What is a statistical statement which specifies that there is a specific value of a population parameter?

A) Null hypothesis B) Alternate hypothesis C) Test statistic D) Parameter E) Decision rule

Soru 9:

Multistage sampling is an extension of _______

A) Simple random sampling B) Stratified sampling C) Quota sampling D) Systematic sampling E) Cluster sampling

Soru 10:

In an investigation, if the confidence level is 0,95 ; what is the significance level of this study?

A) 0,01 B) 0,05 C) 0,50 D) 0,95 E) 0,99

Soru 11:

Which of the following is the null hypothesis for the right sided (upper tailed) test ?

A) H0 : µ1 – µ2 = 0 B) H1 : µ1 – µ2 = 0 C) H0 : µ1 – µ2 < 0 D) H0 : µ1 – µ2 > 0 E) H1 : µ1 – µ2 < 0

Soru 12:

Sample values for a continuous variable (laptop computer's temperature in an hour ; as o C) : 42, 45, 47, 54, and 58. What is the point estimate of the population arithmetic mean?

A) 48.1 B) 48.5 C) 49.2 D) 50.4 E) 52.0

Soru 13:

If you can assign a probability to each object in the population to be selected in to a sample, what kind of sampling is used?

A) Non-probability sampling B) Convenience sampling C) Probability Sampling D) Snowball sampling E) Quota sampling

Soru 14:

In a two population hypothesis testing problem, the sample arithmetic means are 45 and 80. If the z value is calculated, what is the value of numerator for z?

A) -15 B) -25 C) -35 D) 40 E) 70

Soru 15:

Which of the following test is used in case of more than two means of population?

A) F-test B) Q-test C) P-test D) Chi-test E) Wald test

Soru 16:

What will be the degrees of freedom for two samples whose sample sizes are "m" and "n" and if the population variances are assumed to be equal for testing the difference between two means?

A) The smaller of m and n B) m+n-2 C) m+n-1 D) m+n E) m+n+1

Soru 17:

In an interval estimation problem for population arithmetic mean; z =1.96, population standard deviation =12, n=16 and sample arithmetic mean = 28. What is the upper limit of the confidence interval for population mean?

A) 35.89 B) 42.98 C) 49.17 D) 35.79 E) 33.88

Soru 18:

In hypothesis testing, which of the steps below is the first to be followed?

A) Identify the test statistics B) State null or alternate hypotheses C) Formulate a decision rule D) Select a level of significance E) Take a sample and make a decision

Soru 19:

Interval estimation : the limits of the confidence interval are (99, 123), the significance level is 0.01. What is the sample arithmetic mean?

A) 104 B) 11 C) 112 D) 114 E) 117

Soru 20:

Assume that there are two different brands (A and B) producing chocolates. The variance of chocolates are assumed to be different. One chooses 10 chococaltes of brand A and 20 chocolates of brand B and observes that the average weight of brand A sample is 56 gr and brand B is 54 gr. The sample variances for A and B are 1 and 2 gr respectively. What will be the t-statistic and can we conclude that the weights of these brands are different at 0.05 significance level?

A) t=1.65, weight are same B) t=1.81, weights are same C) t=2.98, weights are different D) t=3.34, weights are same E) t=4.47, weights are different