Samples and surveys

When we collect data it's important to know what type of data we're collecting and how to collect it properly.

Problem 1: Qualitative and quantitative data

A survey was given that included data on each student's field of interest, age in years, number of languages spoken, and handedness.
DavidBeccaPaige...
Field of interestcomputer sciencejournalismchemistry...
Age (years)131514...
Languages spoken211...
Handedrightleftright...
question a
Is "field of interest" qualitative or quantitative?

Question b
Is "age (years)" qualitative or quantitative?

Question C
Is "languages spoken" qualitative or quantitative?

Question D
Is "handed" qualitative or quantitative?

Problem 2: Representative samples

question a
Jillian wants to know what percent of students at her school watch sports on TV. Which strategy for sampling will be more likely to produce a representative sample?

question b
Theo wants to know what percent of students at his school have a computer. Which strategy for sampling will be more likely to produce a representative sample?

Problem 3: Sampling methods

Willy wants to find what percent of students at his school drink the milk after they finish their cereal. He is considering the following sampling methods:
question a
He selects every tenth person who enters the school. What type of sampling is this?

question b
He randomly selects 10 students from each grade level (freshman, sophomore, junior, senior). What type of sampling is this?

question c
He randomly selects 50 student names from a hat. What type of sampling is this?