Seçmeli Ara Sınav - Statıstıcs Iı

Soru 1:

The independent random sample sizes are n1 = 180 students and n2 =200 students. Also, the sample mean grades are 80 and 90. Population standard deviations are 20 and 40 respectively. What is the z value for the hypothesis testing?

A) -3.45 B) -4.59 C) -7.6 D) -0.89 E) -1.82

Soru 2:

In a two population proportion problem x1 =50; n1=200; x2=120; n2 =400 then what is the value of joint p value?

A) 0.08 B) 0.12 C) 0.15 D) 0.25 E) 0.28

Soru 3:

The process of estimating a population parameter by a single number derived from the sample is called _______________ estimation?

A) Default B) Unknown C) Interval D) Variable E) Point

Soru 4:

There are 28 red apples, 24 green apples, 16 immature apples, 32 red tomatoes, 16 green tomatoes, and 20 immatue tomatoes in a box. What is the population proportion estimate of immature things in this box ?

A) 5 / 32 B) 9 / 34 C) 11 / 90 D) 13 / 80 E) 15 / 128

Soru 5:

In a two population hypothesis testing problem, the alternate hypothesis sign is not equal and the level of significance 0.05, what is the theoretical value of z from standard normal distribution?

A) 1.88 B) 1.96 C) 2.58 D) 2.33 E) 2.87

Soru 6:

What is a value that defines the characteristic of a whole population called?

A) Parameter B) Mean C) Variance D) Mode E) Median

Soru 7:

Interval estimation : the limits of the confidence interval are (4.1, 5.9), the significance level is 0.05. What is the sample arithmetic mean?

A) 4.15 B) 4.60 C) 5.00 D) 5.30 E) 5.85

Soru 8:

For a statistical test following a normal distribution, the alternative hypothesis is that the mean equals to a thousand and the standard deviation is ? = 24. A sample of 576 observations is randomly selected and the sample average is equal to 1020. What is the test statistic equal to?

A) 5 B) 10 C) 20 D) 30 E) 40

Soru 9:

In a market, a chef selects the first 5 vegetables he sees in the fresh vegetable boxes as her test samples. Which type of sampling method does the chef use?

A) systematic B) convenience C) quota D) stratified E) snowball

Soru 10:

Which one of the following is not one of the reasons of sampling?

A) Cost B) Time C) Average D) Accuracy E) Destructive tests

Soru 11:

What is the third step of hypothesis testing?

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

Soru 12:

The frequency of recovery from illness after therapy A in a sample of 640 is 160. What is the point estimate of population proportion for recovery from illness?

A) 0.95 B) 0.90 C) 0.64 D) 0.25 E) 0.16

Soru 13:

I. The null hypothesis defines what the decision maker’s conclusion is if he/she accepts the alternative hypothesis. II. The null hypothesis H 0 is a statistical statement which specifies that there is a specific value of a population parameter. III. The alternative hypothesis H 1 specifies that there is a difference between the value of a population parameter and a certain value. Which of the given statements can be said about the null and alternative hypotheses?

A) Only I B) Only II C) I and II D) I and III E) II and III

Soru 14:

A new mobile device power bank’s charging time is 5 hours. 50 power banks are selected and tested for their charging time. The average charging time of these power banks is 5.05 hours. It’s assumed that the power bank charging time is normally distributed with a standard deviation as ? = 0.2 hours. What is the sample size (n) according to the situation above?

A) 5 B) 0.5 C) 5.5 D) 50 E) 0.2

Soru 15:

A chocolate factory is examining the sales of their new brand chocolates in two nearby cities. The number of chocolates sold in city 1 is 300 (n1) and 120 of the chocolates were their new brand chocolates. On the other hand, in the city 2, 240(n2) of the sold chocalates, 150 of them were their new brand chocolates. What is the test statistics? ([(1/300) + (1/240)] can be assumed to be equal to 0.25)

A) -2.9 B) -1.9 C) -1.6 D) -1.3 E) -0.9

Soru 16:

Interval estimation : the sample arithmetic mean is 26 and the upper limit of the confidence interval is 33, then what is the lower limit of the confidence interval?

A) 23 B) 21 C) 20 D) 19 E) 17

Soru 17:

In a problem, the variance between samples is 350 and variance within samples is 70. What is the test statistic F according to this information?

A) 0,5 B) 5 C) 15 D) 0,7 E) 0,35

Soru 18:

I. The alternative hypothesis can be expressed in three different ways according to the purpose of the research question. II. H 1 : ? ? ? 0 A hypothesis test whose alternative hypothesis (H 1 ) has this form named as the one-tailed test or one-sided alternative hypothesis. III. Right-tailed and left tailed hypothesis tests are also called a two-tailed test or two-sided alternative hypothesis. Which of these statements about hypothesis testing are true?

A) Only I B) Only II C) I and II D) I and III E) II and III

Soru 19:

____________________________ is the probability distribution of all possible sample means that can be created from a population with a fixed sample size of n.

A) The sampling distribution of the sample variance B) The sampling distribution of the sample standard deviation C) The sampling distribution of the sample mean D) The sampling distribution of the sample median E) The sampling distribution of the sample mode

Soru 20:

Which of the following is NOT a statistical hypothesis?

A) The mean age of students in a classroom is 26.5 years. B) The variance of thefuel consumption of a certain model car under various road and traffic condition is 0.76 litres in 100 kilometres. C) The battery manufacturer claims that the average number of charge cycle is about 900 charge cycles for the specific type of rechargeable batteries D) The proportion of people wearing eyeglasses is almost four times higher than that the proportion of the contact lens users. E) The students who study in a library recall more information than students who study at home.