cogs 14b questions

Question 1

Suppose you are interested in studying the average height of all students in a
specific high school. You measure the height of 100 randomly selected
students from that high school.
Is this group of 100 students a population or a sample?

Answer 1

Sample

Question 2

Imagine you have a dataset that tracks the monthly rainfall in a particular city
over the course of a year. Each data point consists of the month (e.g., January,
February) and the corresponding amount of rainfall in millimeters for that
month. Based on this dataset, what type of graph—bar, line, or scatter
plot—would be optimal to visually represent the variations in monthly rainfall
throughout the year?”

Answer 2

Line graph (continuous numerical data) and tracking single variable
(rainfall over months)

Question 3

Suppose you have a dataset that contains pairs of data points representing
the relationship between a person’s hours of study per week and their
corresponding exam scores. Each data point consists of the number of hours
studied and the exam score achieved by an individual. Given this dataset,
what type of graph—bar, line, or scatter plot—would be optimal to visually
represent the relationship between study hours and exam scores?

Answer 3

Scatter - variables on both x and y axis

Question 4

A researcher working for a record company wants to conduct a study on how
music genre impacts album sales. The researcher decided to pick 3 popular
artists from 3 genres - Drake for Rap, SZA for R&B and Taylor Swift for Pop.
The researcher collects data on the number of album sales for each artist’s
latest album release over a time period. What would be the following in
regards to this study?
- Independent Variable
- Dependent Variable
- Constant Variable

Answer 4

• Independent Variable: Music genre
• Dependent Variable: Album sales
• Constant Variable: Time period

Question 5

Taking the previous question into consideration along with what we have
covered so far in lecture, what would be the optimal graphical representation
of this study?

Answer 5

Line plot - each artist can have their own line, and it would make the
comparison of album sales over time efficient and clear

Question 6

You ask UCSD COGS 14B students for their age, and you want to display this
data using a frequency distribution. Would it be better to used a grouped or
ungrouped frequency distribution?

Answer 6

Ungrouped - optimal to use when smaller amount (less than 20 ) of val
classes

Question 7

I want to present this frequency distribution with a table. Is this an use of
descriptive or inferential statistics?

Answer 7

Descriptive statistics

Question 8

I want to collect the eye colors of all the students in this class. What type of
variable is eye color?

Answer 8

Nominal - represents labels/categories

Question 9

I want to take the height of all the students in the class. What kind of variable
is height? Is it a quantitative or qualitative variable?

Answer 9

Continuous - quantitative variable and can take any value within a range

Question 10

You have a data frame where there are 7 rows, representing each day from the past week. There are 4 columns - day of the week, and temperature at 9am
each day in Kelvin, Celsius, and Fahrenheit. What type of variable is each
measurement?

Answer 10

Kelvin - ratio because 0 represents complete absence of thermal energy
Fahrenheit & Celsius - interval because the temperature 0 does not
indicate the absence of temperature