MTHS101 - Data Management

Mathematics in the Modern World

Data Management

Department of Mathematics
College of Science and Engineering
Ateneo de Naga University

Learning Outcomes

• Use a variety of statistical tools to process and manage numerical data;

• use methods of linear regression and correlations to predict the value of a variable given certain conditions; and

• advocate the use of statistical data in making important decisions.

Multiple Choice

What is the science of conducting studies to collect,

organize, summarize, analyze, and draw conclusions

from data?

• Number Theory

• Statistics

• Abstract Algebra

• Calculus

Multiple Choice

What do you call a subset of a population?

• Parameter

• Sample

• Statistic

• Data Set

Multiple Choice

These are values that variables can assume.

• Characteristcs

• Data

• Numbers

• Answers

Multiple Select

Which of these are the two types of variables?

• Qualitative Variables

• Limited Variables

• Adjunct Variables

• Quantitative Variables

Multiple Select

Select the two branches of Statistics?

• Numeric

• Descriptive

• Hypothetical

• Inferential

LET'S START!

TWO BRANCHES OF STATISTICS

Multiple Choice

A graduate student at the University of Newport conducts a research project about communication in the U.S. She mails a survey to all of the 500 adults that she knows. She asks them to mail back a response to this question: "Do you prefer to use email or snail mail (the U.S. Postal Service)?" She gets back 65 responses, with 22 of them indicating a preference for snail mail. She then reported that 22/65 = 33.8% of adults prefer to use snail mail. What is the population?

• The 33.8% of adults in the sample that prefer snail mail.

• The proportion of all adults in the U.S. that prefer snail mail.

• All adults in the U.S.

• The 500 adults that she knows.

Multiple Choice

A graduate student at the University of Newport conducts a research project about communication in the U.S. She mails a survey to all of the 500 adults that she knows. She asks them to mail back a response to this question: "Do you prefer to use email or snail mail (the U.S. Postal Service)?" She gets back 65 responses, with 22 of them indicating a preference for snail mail. She then reported that 22/65 = 33.8% of adults prefer to use snail mail. What is the sample?

• The 65 adults that responded.

• The 500 adults that she knows.

• All adults in the U.S.

• The 22 adults that prefer snail mail.

VARIABLE

a characteristic or attribute that can assume different values

DATA

the values (measurements or observations) that the variables can assume. A collection of data forms a data set.

Multiple Choice

Suppose you want to estimate the percentage of videos on YouTube that are cat videos. It is impossible for you to watch all videos on YouTube so you use a random video picker to select 1000 videos for you. You find that 2% of these videos are cat videos. Which of the following is a variable?

• Percentage of all videos on YouTube that are cat videos.

• 2%

• A video in your sample.

• Whether or not a video is a cat video.

Multiple Choice

Which of the following is NOT a qualitative variable?

• Eye Color

• Sex

• Course

• Age

Multiple Select

Which of the following are subject variables?

• Sex

• Screen time per day

• Personality Type

• Assigned Reading Material

Multiple Choice

What level of measurement is shirt size?

• Nominal

• Ordinal

• Interval

• Ratio

Multiple Choice

What level of measurement is hometown?

• Nominal

• Ordinal

• Interval

• Ratio

Multiple Choice

What level of measurement is temperature?

• Nominal

• Ordinal

• Interval

• Ratio

Multiple Choice

What level of measurement is test score?

• Nominal

• Ordinal

• Interval

• Ratio

Major Considerations in Collecting Data

• Nature of the problem

• Objectives of the researcher

• Types of data required

• Sources of data

Sample Size Determination

Slovin's Formula is used to calculate the sample size (n) given the population size (N) and a margin of error (e).

Fill in the Blank

A researcher would want to make a socio-economic survey of a

school with a population of 5,000 students. If he allows a margin

of error of 5%, how many students must he take into sample? (Input the value for the sample size, rounded to the nearest whole number.)

Important Note

Samples should be as large as a researcher can obtain with a reasonable expenditure of time and energy. A recommended minimum number of subjects is 100 for descriptive study, 50 for correlation study, and 30 in each group for experimental and causal-comparative study.

Multiple Choice

Suppose there is a population N = 200 and the researcher needs a

sample of n = 25. What is the value of k?

• 7

• 8

• 9

• 25

Multiple Choice

Given a population N = 365, the researcher grouped the

respondents according to sex on which 219 are female and 146 are

male. Using stratified sampling, how many respondents will be

obtained from each strata? (Assume that the margin of error

e = 5%)

• 100 Males, 50 Females

• 76 Males, 115 Females

• 75 Males, 114 Females

• 115 Males, 76 Females

Reasons for Using Non-random Sampling Methods

• Want to get a feel of the market before launching or producing a certain product

• Lack of logistics or inadequate knowledge in the use of random methods

• The validity of the sample is based on the soundness of the judgment of whoever to make the choice.

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