Stats

Question 1

Population

Answer 1

The set of all measurements of interest to the investigator. What the investigator wants to study, analysis, and make conclusions//inferences about.
Examples:
All people in the United States
All cats on Mars
All bugs in your hair

Question 2

Sample (in other words, sample size)

Answer 2

A small group within/reflective of the group people want to study that is included for this experiment
Ex:
100 people in the United States
50 Cats on Mars
5 bugs in your hair

Question 3

Experimental Unit or Element

Answer 3

Individual or object on which a variable is measured

In other words, whatever you have to give to the sample in order to gain data from it
Ex: the people in the United States
bugs on Mars

Question 4

How do people collect from the sample?

Answer 4

Surveys, observations, interviews, etc.

Question 5

Variable

Answer 5

whatever attribute you are aiming to find or a measurement within your sample/experimental unit

Ex: height of people in United States
color of bugs in your hair

Question 6

Measure of center or central tedency

Answer 6

Basically the average in a data set, also known as center of the “distribution” (can be mean, median or mode)

Question 7

Sample mean

Answer 7

Sum of all sample data over count of data(indicated by xi)

Question 8

Population mean

Answer 8

Sum of all population data, indicated by mew(μ) over true population count
Excel formula: average(data)

Question 9

Median

Answer 9

Essentially the middle value in an ordered set of numbers (if odd count, then there’s middle value, if even then it’s average of two middle ones)
Eliminates outliers(very extreme values)
Excel formula: median(data)

Question 10

Mode

Answer 10

The most frequent value in the data set(what values occurs the most)
Frequency table, the most frequent value(highest frequency)on the graph is the mode

Question 11

Frequency

Answer 11

Relate frequency to mode(if value has most frequency = it’s the mode), amount of times a certain values shows up in a data set

Question 12

Bimodal distribution

Answer 12

Two modes

Question 13

Multimodal distribution

Answer 13

Data has more than two modes

Question 14

What is sometimes the reason for bimodal or multimodal distributions?

Answer 14

This is because we mix two kind of populations into one. For example, heights of men and woman. Generally, men have the most common height of 5’9, while woman it’s probably like 5’5 or something, those are two completely different values yet it’s still bimodal.

Question 15

mode.sngl excel formula

Answer 15

if there are two modes, this gives the lowest of the two

Question 16

mode.multexcel

Answer 16

Returns ALL modes from dataset

Question 17

Weighted Mean

Answer 17

When some things are weighted more than others and can impact the mean more (because they are given more importance)

Question 18

Anchor

Answer 18

Makes a term constant while you copy and paste the formula

Question 19

Variance

Answer 19

a way to measure how spread out numbers are from their average. It tells us how much the values in a data set typically differ from the mean (average).

Question 20

Standard deviation (and how it’s diff from normal population and sample variance)

Answer 20

Essentially it’s variance (both sample and population) squared

Question 21

Sample vs population

Answer 21

Sample data is data only from a portion of the population, and people assume it reflects all of the population