The answers to the questions are given below:
‘Score’ will be a discrete variable because it can take only whole numbers like 1, 2, 3and so on. Its value cannot be a fraction. The score is counted by the number of goals. So this figure cannot take values like 2.5, 4.7 etc.
The variable ‘number of minutes to commute to work’ can take any value within an interval. It can be 1 hour, 0.25 hour, 2.6 hours and so on. It can take fractional values. In fact there can be infinite values within a range that this variable can take as the time can have any value within a feasible range.
The difference between population and sample:
When the data on a particular set of variables is collected for all the members concerned in the survey, it is known as the population. That means population includes all the items that have to be assessed. For example if we are collecting data on the income and education of the personnel in a firm, all the personnel involved in the firm form the ‘population’. Sometimes the population is too large. It becomes difficult or sometimes impossible to take observations on such a huge population. In such a case a representative set of members are selected on whom the required information is collected. This representative set is known as the sample.
When the population size is large it becomes time consuming and tedious to collect data on the huge population . To save time, energy and money we have to take recourse to sampling. For example if we want to assess the quality of corn produced in different fields in a particular area we cannot check each and every grain of the cereal. We have to take handful and assess their quality to get an idea about the whole. Let us consider another example. Suppose we want to find how the demand for a particular product, say ice-creams varies with the income level and age of the consumers in a country. If we have to collect data on each person the survey will take a very long time. In such a case we have to conduct a sample survey of consumers.
If a coffee vending machine dispenses 6 oz of coffee per cup on an average it does not mean it does so every time. This means sometimes it may dispense more than 6 oz and sometimes less than that . But the amount it dispenses remains near to 6 oz. So if a vending machine occasionally dispenses 4 oz it cannot be said that its average dispensing rate is not 6 oz.
A voter’s registration list is not a statistical information. It registers the identities of the citizens of the country who have reached the minimum age for voting. This list is revised at regular intervals. A census of adult population will not give the idea about the voter’s list.
There are a number of software packages available that help in faster analysis of statistical data. Computers make the job of statistical estimation easier. It does not require the person to do complex calculations as it is handled by the computer itself. So nowadays there is a greater amount of information flow. Statistics has become important for a large section of the people who can now make a better analysis of data and produce meaningful statistical details. This creates productive information for industry, government, consumers and many other sections of the society.
References
Bulmer, M. (1979). Principles of Statistics. New York: Dover Books.
Das, N. (1991). Statistical Method. Kolkats: M.Das&co. .
Sarma, K. (2010). Statistics Made Simple: Do it Yourself on Pc. PHI Learning.
