Question

Using key terms, create a scenario where you can find a population, a sample, the parameter, the statistic, a variable, and data. Post your scenario and provide a detailed description using the key terms. After reviewing the information, what did you learn about your target population?

Answer 1

SCENARIO:

Suppose we are interested to know the average height and weight of the students in the class. Let’s say, we have 200 students in the class including both male and female. So here population is the whole class (200 students). Out of them we randomly selected 20 students. We will consider these 20 students as our sample. Here population parameters are values that are calculated from all the values in the population. Population parameters describe the characteristics of the population. Population parameter is also a fixed value (Average height and weight of 200 students). A sample statistic is a value calculated from the values of the sample that means from 20 students. Sample statistic is a random variable because if we change the sample the average value of height and weight will change. If the population is too large in that case we estimate (approximate value) the population mean and variance from the sample that means population mean (average value) will be almost same/approximately same with the sample mean (average value). In this example, we calculate the average value height and weight of those 20 students (sample) then we can say that the average value of height and weight for the population (200 students) would be approximately same. Here “Height”, “Weight” are the variables. If we increase our sample size (from 20 to 50) in that case population mean (average value) will be closer to the sample mean (average value).

Definition of Key Terms:

Population: Population refers to the total set of observation that we want to study. In the above scenario, 200 students are considered as population.

Sample: A set of observation/data selected/collected from the population. It is a subset of the population. In the above scenario, 20 students are considered as sample.

Parameter: Parameter is a characteristic of a population. Average height and weight of 200 students.

Statistic: Statistic is a characteristic of a sample. Average height and weight of 20 students.

Variable: Height, Weight and Sex are the variables.

Data Set: (Sample Data Set)

Serial Number	Sex	Height (cm)	Weight (Kg)
1	M	175	75
2	M	177	72
3	M	171	79
4	F	169	65
5	F	174	68
6	M	180	87
7	F	165	67
8	F	178	65
9	M	164	76
10	M	168	78
11	M	163	70
12	F	170	59
13	M	154	71
14	F	167	58
15	F	175	63
16	M	174	78
17	M	169	75
18	M	172	87
19	F	165	68
20	M	185	91

Based on the above sample we can calculate the average value of the height and weight. We can also get the value across male and female. We can calculate the maximum and minimum value of height and weight for both male and female. We get the approximate/estimated average value of height and weight of the target population. Apart from that we can draw different diagram (histogram) based on our sample and can calculate the distribution of the variables. That means we can get overall idea about the target population.