I need only explanation to these basic level questions for my son

1. The archaeological site of Tara is more than 4,000 years old. Tradition states that Tara was the seast of the high kings of Ireland. Because of its archaeological importance, Tara has received extensive study. Suppose an archaeologist wants to estimate the density of ferromagnetic artifacts in the Tara region. For this purpose, a random sample of 55 plots, each of size 100 square meters, is used. The number of ferromagnetic artifacts for each plot is determined.
(a) Identify the variable
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?

2. Categorize these measurements associated with a robotics company according to level: nominal, ordinal, interval, or ratio.
(a) A salespersonís performance: below average, average, above average
(b) Price of companyís stock
(c) Names of new products
(d) Temperature (Fahrenheit) in CEOís private office
(e) Gross income for each of the past five years
(f) Color of product packaging

Q3
Samplings: Students in Class. Suppose you are assigned the number 1, and each of the other students in your statistics class calls out consecutive numbers until each person in class his or her number. Explain how you could get a random sample of four students from your statistics class.
(a) Explain why the first four students walking into the classroom would not necessarily form a random sample.
(b) Explain why four students coming in late would not necessarily form a random sample.
(c) Explain why four students sitting in the back row would not necessarily form a random sample.
(d) Explain why the four tallest students would not necessarily form a random sample.