Statıstıcs I Ara 2. Deneme Sınavı
Toplam 20 Soru1.Soru
The figure above is a dot plot showing Mathematics grades in class A by gender. Which of the statements is not correct depending on the information above?
The highest grade of males is 70. |
The highest grade of females is 90. |
There are more female students than the male students in class A. |
There are groupings around 60 and 70 in male students. |
There are groupings around 60 and 75 in female students. |
There are 3 female students who got 70 and 3 who got 75, which is the highest number of females around these grades.
2.Soru
What is the midrange of the following data set with frequency in paranthesis?
14 (2), 34 (4), 38 (3), 44 (3), 96 (2)
96 |
55 |
34 |
26 |
14 |
Midrange = (x_min + x_max) / 2 = (14 + 96) / 2 = 55
3.Soru
Which of the following is not true about histogram?
A histogram is drawn for continuous data. |
In order to draw the histogram of the data, a large sample is needed. |
A histogram gives information about the centre, shape and symmetry of the data. |
A histogram can also be used to check out the normality. |
A histogram doesn't give information about the peaks and extreme values. |
Histograms will help us to identify the centre, shape and symmetry of the data. A histogram can tell us about the peaks and extreme values..
4.Soru
I. the shape of the distribution of the data
II.the relation between two sets of data
III.the most repeating observations
Which of the things above a properly created graph can report in a visual form?
I |
I and II |
II |
II and III |
I, II and III |
A properly created graph can report various information of the data in a visual form. For instance, the shape of the distribution of the data, the relation between two sets of data, the most repeating observations, outliers, peaks, summary statistics (minimum, maximum, range, mean, median) etc. can be identified from graphics. The correct answer is E.
5.Soru
- Element
- Variable
- Concept
- Case
Which of the above are the key components of a data set?
I and II |
II and III |
I, II and III |
I, II and IV |
I, III and IV |
Several characteristics define a data set’s structure and properties. Element, Variable, Case and Observation are the key components of data sets.
6.Soru
"It is often used to display the trends in a continuous data over a period of time. It also works well with discrete (ordered) or categorical types of data. It is constructed by intersecting the points by lines on the x-axis. Some of them are used to draw in two or three dimensions. Additionally, some of them are very helpful to show the relationships for multivariate data."
What kind of a graphic is described in the paragraph above?
Bar chart |
Pie chart |
Histogram |
Dot plot |
Line chart |
Line chart is often used to display the trends in a continuous data over a period of time. Line chart also works well with discrete (ordered) or categorical types of data. The chart is constructed by intersecting the points by lines on the x-axis. Some line charts are used to draw in two or three dimensions. Additionally, some of the line charts are very helpful to show the relationships for multivariate data.The correct answer is E.
7.Soru
To prove that aspirin is the cause of the improvement in health, what type of research needs to be conducted?
To prove that aspirin is the cause of the improvement in health, what type of research needs to be conducted?
case |
observation |
statistical |
experiemental |
report |
In order to be able to prove that aspirin is the cause of the improvement in health, an experiment needs to be conducted where conditions are controlled between those taking aspirin and those not taking it. Such an experiment might be designed as follows, restricted to men, for example, since the effects are suspected to be different for men and women.
8.Soru
Consider the pie chart constructed based on the data presented above. What is the angle of the studying?
120 degrees |
90 degrees |
60 degrees |
45 degrees |
30 degrees |
The total time for the activities is 24 hours. 360 degrees represent 24 hours. So, one hour represented with 360/24 degree=15 degree. The angle of studying equals to 15x4=60 degrees.
9.Soru
- A researcher recorded the observed daily closing prices of several publicly traded common stocks for a financial study.
- A sales manager of a company conducted a research about purchases of a specific product of the company.
- A university student who successfully completed the course filled out the assessment questionnaire about the lecturer.
What are the correct definitions of the data collection methods given above?
I-Observation method, II-interview method, III-self-enumeration method |
I-interview method, II-observation method, III-enumeration method |
I-self-enumeration method, II-interview method, III-observation method |
I-observation method, II-self-enumeration method, III - interview method |
I-interview method, II-enumeration method, III- observation method |
Observation is making direct examination and taking measurements of an ongoing activity. In other words, observation is way of obtaining data by watching behavior, events, or noting physical characteristics in their natural setting. One of the most common methods of collecting data from individuals is interviewing. In an interview procedure, a researcher or observer asks the questions from a questionnaire and records the individual’s answers. In a self-enumeration method, individuals answer the questions printed on a questionnaire paper, or displayed on a computer monitor. In other words, self-enumeration method refers to the completion of survey questionnaires by the respondents themselves.
10.Soru
For an observation that results in values 6,7,3,4,3,5,6 what is the 30% Winsorized mean of the group?
2 |
3 |
4 |
5 |
6 |
The Winsorized mean can be calculated with the remaining values after replacing a certain number or the proportion of the values at the low and high end of the sorted data. First the data set is ordered from smallest to largest 3,3,4,5,6,6,7 then we will find how many data points will be replaced, k, since the winsorizing is 30% and there are 7 observations, the value of k is k = np = 7×0.30 = 2,1 which is nearly 2. Therefore, 2 observation from each end of the sorted data will be replaced with those next in magnitude, these observations are as follows, 3 is replaced with 4 and 7 and 6 is replaced with 6. The set yields to 4,4,4,5,6,6,6. The 30% Winsorized mean of the data set is (4+4+4+5+6+6+6)/7= 5. The answer is D.
11.Soru
Which of the following is preferably used to visualize a trend of continuous data over time?
Histogram |
Stem-and-leaf |
Bar chart |
Pie chart |
Line chart |
Line chart is often used to display the trends in a continuous data over a period of time.
12.Soru
An advertisement company conducts a survey on parfume preferences of adults in a city. The researcher collects a sample of 200 people of whom 170 are male. What type of error does the researcher make?
Error in population spesification |
Error in measurement |
Error in sampling |
Error in modelling |
Error in analyzing |
Since almost half of the population is female, he is making a mistake in sampling. The parfume preferences of males and females could be different and his sample is male biased.
13.Soru
Customers asked to respond to the following statement. “The picture quality of your TV is satisfactory”. Customers responded to the statement as 1=Strongly Disagree, 2=Disagree, 3=Undecided, 4=Agree, and 5=Strongly Agree.
If the measurement categories and the number of responses within a given measurement category are used, what method of data organization is implemented in the case specified above?
Raw data |
Grouped Frequency Distribution Table |
Frequency Distribution Table |
Cumulative Frequency Distribution Table |
Relative Frequency Distribution Table |
Sometimes raw data in a frequency distribution table yield more useful information. To construct a frequency distribution table, the measurement categories and the number of responses within a given measurement category are used.
14.Soru
Your professor is surveying you and asking your gender, hometown and branch. What form of data is s/he dealing with?
nominal |
ordinal |
interval |
ratio |
continuous |
Data such as gender, hometown and branch do not represent a computational score. They can only be used to categorize the sample.
15.Soru
Which of the following is FALSE about histogram ?
It is very similar to a bar chart. |
It shows continuous data. |
It is drawn for qualitative data. |
It can tell about the peaks and extreme values. |
It helps us to identifty the symmetry of the data. |
Histogram is a graph that is very similar to a bar chart except that bar charts are drawn for qualitative data but histograms are drawn for continuous data. The correct answer is C.
16.Soru
A researcher goes to a bus station and takes record of the number of people getting into a bus in that station everyday. Which type of data collection method is the researcher using?
Interview |
Observation |
Self-Enumeration |
Questionnaire |
Sampling |
The researcher is making an observation.
17.Soru
- Can be drawn by hand easily while collecting data
- Useful when observation count is less than 50
- Generally used to investigate univariate data
Which of the following data display types do these features identify?
Dot plot |
Stem-and-Leaf |
Bar chart |
Histogram |
Pie chart |
Dot plot is almost the easiest of the graphs. It can be drawn by hand easily while collecting data.
Dot plot will be very useful when the number of objects in our study is rather small such as up to 50
observations. Dot plot is generally used to investigate univariate (quantitative) data, but sometimes it is
used to compare two variables.
18.Soru
Which of the following statements is true?
Mean of a left-skewed distribution is larger than the mode of it. |
Median of a left-skewed distribution is larger than the mode of it. |
Mean of a right-skewed distribution is smaller than the mode of it. |
Mode and median of a normal distribution are larger than its' mean. |
Mean, mode and median of a normal distribution are equal. |
Only the statement in E is true. For left-skewed distributions mean<median<mode, and for right-skewed distributions mean>median>mode. But for normal distributions all these measures are same.
19.Soru
What is the arithmetic mean of the following data?
(2, 4, 5, 6, 7, 8, 9, 9, 9, 14)
3.3 |
4.3 |
5.3 |
7.3 |
10.3 |
mean = total / n
mean = 73 / 10
mean = 7.3
20.Soru
What is the geometric mean of the following data set?
8, 27, 64
18 |
24 |
25 |
33 |
36 |
(8 x 27 x 64)-3 = 2 x 3 x 4 = 24
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