Bus102 statistics chapter 1

Question 1

why study statistics? لماذا دراسة الاحصاء؟

Answer 1

1. To be able to collect data everywhere and require statistical knowledge to make the information useful.
2. Statistical techniques are used to make professional and personal decisions.
3. A knowledge of statistics is needed to understand the world and be conversant in your career.
4. statistics will help you make more effective decisions.

Question 2

what is meant by statistics? ما المقصود بالإحصاء؟

Answer 2

1. statistics: The science of collecting, organizing , presenting ,analyzing , and interrupting data in a particular way.

Ex: the average number of points earned by students in that one math class at the end of the term .

Question 3

What are the four types of statistics ?

ما هي الأربعة أنواع الإحصائيات؟

Answer 3

1. Descriptive statistics: Methods of organizing ,summarizing ,and presenting data in an informative way.
   Descriptive statistics:
2. can be used to organize data into a meaningful form.
3. can summarize data and provide information that is easy to understand.
4. Inferential statistics : The methods used to estimate a population on the basis of a sample.
   Inferential statistics:
5. can be used to estimate properties of a population.
6. it can make decisions based on a limited set of data.
7. Population statistics: The entire set of individuals or objects of interest or the measurements obtained from all individuals or objects or interest.
8. Sample statistics: A portion or part of the population of interest.

Question 4

what are the two types of variables?

Answer 4

1. Qualitative Variable: An object or individual is observed and recorded as a non -numeric characteristic or attribute.
   Example : Gender, state of birth , eye color.
2. Quantitative Variable: A variable that is reported numerically.
   Example: balance in your checking account, the life of a car battery, the number of people employed by a company .

Quantitative variables can be :
Discrete variables are typically the results of counting values have gaps between the values .
EX: the number of bedrooms in a house, the number of students in a statistics course.

Continuous variables are usually the results of measuring something .Can assume any value within a specific range.
EX: the air pressure in a tire, duration of flights from Orlando to San Diego.

Question 5

what are the four levels of measurement ?

Answer 5

1. Nominal scale: is a scale used for labeling variables into distinct classifications and doesn’t involve a quantitative value or order. It is the lowest level of measurement.
   Ex: Classifying m and m candies by color , identifying students at a football game by gender.
2. Ordinal scale: is a variable measurement scale used to simply depict the order of variables and not the difference between each of the variables. The rankings are known but not the magnitude of differences between groups.
   EX: The list of top ten states for best business climate ,student ratings of professors.
3. Interval Scale: is a numerical scale where the order of the variables is known as well as the difference between these variables. There is no natural 0 point.
   EX: The Fahrenheit temperature scale ,dress sizes.
4. Ratio Scale :is a variable measurement scale that not only produces the order of variables but also makes the difference between variables known along with information on the value of true zero. The highest level of measurement. The 0 point represents the absence of the characteristic.
   EX: wages, changes in stock prices, and weight.