Mode is the most frequent value in a data set.

First we have to reorder the ages in an increasing or decreasing order. Let's do it in an increasing order. Then the ages will be:

4,4,5,5,6,8,8,9,10,10

Since there are 10 observations the median will be the average of the 5th and 6th observations. Thus,

median=(6+8)/2=7

The information about several subgroups of each category can be shown by a grouped bar chart. It can be plotted in horizontal or vertical directions similar to simple bar chart. In grouped bar chart, for each main category there are different sub-categories. In this chart the main categories are the names of the students and the subcategories are the activity types. The correct answer is B. 

The number of students who travel home by car is the smallest so travelling by car will have the smallest portion on the pie chart. The correct answer is A.

the world today abounds in textual data. Words, SMSs, tweets, social media posts, verbal responses in questionnaires, these can all be treated as data. Some recoding will be necessary, since text is not numerical. Frequently occurring words can be counted, the lengths of sentences can be measured,
the number of words used just once can be identified, and so on, in order to create quantitative variables from text. Textual data have been used, for example, in identifying the author of threatening letters, in comparing political party manifestos, in classifying respondents in a survey who give answers to openended questions.

Ordinal scales of measurement have the property of both classifying and magnitude. Subjects are categorized i­nto d­ifferent rank ordered groups. Each value on the ordinal scale has a unique meaning, and it has an ordered relationship to every other value on the scale.

Bar chart or sometimes called bar graphs are typically used to compare counts, frequencies, total number of categories, objectives, amounts etc. It is used for the graphical representation of the qualitative data. Bar chart is the graphical representation of frequencies by rectangles (or bars) with lengths (or heights) proportional to the frequencies of observations. Depending on the variable type and grouping, it is possible to create many types of bar chart

The highest frequency (18) is observed for 45, therefore mode is 45.

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

eyeglass is variable, not data. pg. 14. Correct answer is A.

The world today abounds in textual data. Words, SMSs, tweets, social media posts, verbal responses in questionnaires, these can all be treated as data. Some recoding will be necessary, since text is not numerical. Frequently occurring words can be counted, the lengths of sentences can be measured, the number of words used just once can be identified, and so on, in order to create quantitative variables from text. Textual data have been used, for example, in identifying the author of threatening letters, in comparing political party manifestos, in classifying respondents in a survey who give answers to openended questions.

As also understood from the information given, the correct answer is C. “Verbal responses in questionnaires” and “Social media posts” need recoding in order to create quantitative variables. “Frequently occurring words”, “The lengths of sentences” and “The number of words used just once” are the ones which are recoded in order to create quantitative variables.

There are 200 workers in factory and in total 180 them are below 50 years old. Thus the cumulative frequency is 180/200=0.9 (90 %)

statistics I course book

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.

Analysis is not a component of data sets. Analysis can be done over datasets.

arithmetic mean = sum of numbers / no of numbers = (4 + .. + 32) / 10 = 112 / 10 = 11.2