Statıstıcs I Ara 6. Deneme Sınavı

Midrange is an arithmetic mean of the extremes in both end of the data set. It only needs the smallest
value and the largest value to be given. The arithmetic mean of the maximum and minimum value of the set gives the midrange. For the set 6,7,3,4,3,5,6 the minimum value is 3 and the maximum value is 7 therefore the midrange would be equal to (7+3)/2 = 5. The answer is A.

That type is ratio scale. An example of this type scales is age. The age of a person can be zero at minimum. So if one person is 60 years old, he/she is 3 times older than a person who is 20 years old.

Nominal scale classifies things into qualitative different classes. Gender is qualitative.

The first role of Statistics is to reduce this mass of complex data to a simpler form in order to facilitate understanding and learning from the data. This is often done by making graphical representations of the data. Statistics can make a lot of numerical data easily understandable. The world today abounds i­n textual data. Words, SMSs, tweets, social media posts, verbal responses in questionnaires, these can all be treated as data. Climate data, measurements from tens of thousands of weather stations across the world, is an example of big data.

Bigdata are mostly used in following areas:

• Commerce (especially online electronic commerce),
• Biomedicine (especially in genetics), climate data,
• Transport (for example in the airline industry)
• Climate data
• Insurance
• Finance

What are the “big data” sets today and where do they come from? These are mostly found in the following areas:

• Commerce, especially online electronic commerce
• Finance, for example share prices on stock markets, all managed electronically
• Insurance, all the premiums, incidents, actuarial transactions in an insurance company
• Biomedicine, especially in genetics, where information is literally exploding as gene-sequencing reveals and codes the total genetic profile of a person
• Transport, for example in the airline industry, all the flights, all the passengers
• Climate data, measurements from tens of thousands of weather stations across the World

As also understood from the list given, the correct answer is E.

quantitative interval. pg. 8. Correct answer is E.

Data collection by observation procedure has some advantages and limitations. The advantages are:

1. The direct recording of the data avoids problems such as incomplete or distorted recall.
2. Data can be obtained continuously over an extended period of time.

The limitations are:
1. The observer or the instrument to be used for data gathering must be able to record the events correctly. For example, human observers must get through training about the study and the data to be collected and so that different observers will record the same events in the same manner.
2. The individuals included in the study might be aware of this fact and then altered their behavior, decision or answers. This leads to bias in the study.

Gender is a nominal categorical variable.

Statisticians are trained to interpret and analyse data. This profession mainly deals with the analysis of data; not to check and decide for other profesion lines.

Temperature in Celsius does not have an absolute zero. Talking about 20 degrees and 40 degrees, you cannot say its twice warmer but you can say it is 20 degrees more/less. So, the measurement is interval.

The other main type of data (see Fig. 1.4) is called continuous, or quantitative, for example data on variables “blood pressure”, “age” and “income”. These are observations of variables on continuous scales, usually rounded in some convenient way. For example, although age is a continuous time variable, and we are getting older all the time by seconds, minutes and hours, someone’s age is almost always rounded to the number of years completed. There is a subtle difference between interval-scale and ratio-scale continuous data, which is worth mentioning here. Age is an interval-scale variable: to compare two children of ages 10 and 12, we would compute the interval difference, i.e. 2 years. We would not say the 12-year old is 20% older than the 10-year old. But comparing prices or incomes, for example, we would tend to compute percentage differences, making them ratio-scale variables. A good example is the inflation rate, comparing the prices of a basket of products over time, not as a difference but as a percentage. As a general rule, most data on monetary values and those coming from physical measurements (e.g., lira, gold price, centimeters, kilograms) are ratio-scale variables. Other measures of time are interval-scale variables (the word “interval” gives you a clue to that!), for example hours of sleep (on Sundays I sleep an hour longer - I would not say I sleep 14% longer) and time to run 100 meters (e.g., at the 2009 World Championships in Berlin, Usain Bolt shaved more than a tenth of a second off his record, clocking 9.58 seconds - we wouldn’t say he reduced the time from 9.69 seconds by 1.1%).

As also understood from the information given “Age”, “Hours of Sleep” and “Time to Run 100 meters” are interval scale variables, so the correct answer is C. “The Inflation Rate” and “Gold Price” are ratio-scale variables.

30 : occurs most often, it is repeated 4 times

Data come in various forms and are measured in different ways. For example, a doctor measures your blood pressure with an instrument, a survey researcher asks you a question and you give a verbal response, you go on holiday to a particular country, you are at a certain age and have a certain income, you have a grade for a completed university course, or this past week you have gone to the supermarket a certain number of times, and bought a certain basket of products, etc. Blood pressure, question response, country, age, income, course grade, number of supermarket visits and purchased products, these are all statistical variables. The observations made on these variables constitute the data. The subjects or individuals or companies on which these observations are made are called cases. Thus, cases might be a group of tourists entering Turkey, for each of whom we have data on which country they come from, how many days they plan to stay in Turkey, what their tourism objectives are (e.g., cultural events, beach holiday, etc.). Or cases might be hospital patients, on whom we have measured the standard medical indicators such as blood pressure, cholesterol levels, blood sugar, and so on.

As also understood from the information given a group of tourist entering Turkey is case, so the correct answer is A. “which country they come from”, “how many days they plan to stay” and “what their tourism objectives are” are statistical variables.

Interval scales of measurement have the properties of classifying, magnitude, and equal  intervals. While the ordinal scales of measurement show that individuals have more or less something than the others,  interval scales have more precise information indicating how much of something individuals have.

10, 12, 14, 16, 22, 28, 48

16 is the middele value of the set. The correct answer is C.

A pie chart is usually used for categorical data. In pie chart components or outcomes of a total frequency is shown as sectors of a circle. The shape resembles to a pie, hence the name of the chart. In pie chart, the categories are divided in to slices/sectors. Each slices’ size is proportional to the total number of objects. The drawing of a pie chart involves the calculation of angles for each slice/sector. Find the calculation table and the chart below.

In observational studies, researchers observe subjects and measure variables of interest without any intervention to the subjects. In this case, the teacher wants to learn if the new strategy affects the learning. The researcher needs to manipulate some of the variables and try to determine how the manipulation influences other variables.  

Simple bar chart is used to represent discrete values for each category for a given variable on x-axis (horizontal). The y-axis (vertical) shows the actual numbers that are the bar heights for the corresponding category. Thus, the graph should be;