1. Principles of Sampling
● What is the difference between population and sample?
- A population is the whole number of values in which you can take
samples. Samples are sub-group taken from the population
● A sample has to be drawn from 5 different sections composed of 300
students as shown in the table below. How will you draw the sample using
stratified sampling method, using 5% margin of error? show the solution and
the sample you will get per section.
Section
No of students
Solution
BSMD 1Y1-1
66
172
300
×66
38
BSMD 1Y1-2
52
172
300
×52
30
BSMD 1Y1-3
75
172
300
×75
43
BSMD 1Y1-4
59
172
300
×59
34
BSMD 1Y1-5
48
TOTAL
300
172
300
×48
Sample per section
28
173
2. Data Presentation
● When you construct a table, when might it be beneficial to use relative rather
than absolute frequencies?
- Relative frequency tables are more beneficial when you are trying to
compare two or more categories within the same table.
● What types of graphs can be used to display nominal or ordinal observations?
Discrete or continuous observations?
- For nominal or ordinal data, Bar graphs and Pie charts the recommended
graphs
- For discrete and continuous data, Histogram is the most recommended
since it is used to summarize data that are measured in interval scale.
● The reported numbers of live births in the Philippines for each month in the
period January 1995 to December 1996 are listed below:
MONTH 1995
NUMBER
(THOUSANDS)
MONTH 1996
NUMBER
(THOUSANDS)
January
325
January
334
February
312
February
304
March
346
March
360
April
340
April
330
May
355
May
361
June
342
June
333
July
358
July
352
August
346
August
350
September
365
September
357
October
355
October
345
November
324
November
332
December
342
December
325
a. Construct a line graph displaying the reported number of live births over time.
b. Based on this two-year period, do you think the number of live births follows a
seasonal pattern in the Philippines?
-
Based on the data gathered in the year 1995 and 1996, I can tell that
there is really a seasonal pattern since both variables do not have a
drastic difference with each other specially in the months of march and
november.