Intro/Chapter 1

Question 1

Descriptive Statistics

Answer 1

Reducing a closed set of data into key features

Question 2

Inferential Statistics

Answer 2

Drawing conclusions about a larger group than you have data for; generalizations

Question 3

3 steps of Inferential Statistics

Answer 3

1) Estimating/ Creating generalization
2) Testing the hypothesis
3) Fitting to a statistical model

Question 4

2 Types of Numerical Data

Answer 4

continuous and discrete numerical data

Question 5

Continuous Numerical Data

Answer 5

Data in a range, e.g: time, length

Question 6

Discrete Numerical Data

Answer 6

Counted integers

Question 7

2 Types of Categorical Data

Answer 7

Nominal and ordinal categorical data

Question 8

Nominal Categorical Data

Answer 8

No natural order to the categories, e.g: gender, colors

Question 9

Ordinal Categorical Data

Answer 9

A natural order to the categories, e.g: weekdays, scales on a test

Question 10

Confounding Variables

Answer 10

variables that varies both the independent dependent variable, making an apparent, but not valid correlation.

Question 11

Population

Answer 11

all subjects/specimens of interest

Question 12

Sample

Answer 12

subset of population of size ‘n’

Question 13

Histogram

Answer 13

basically a bar chart that plots y as frequency

Question 14

Which side does the histogram favor?

Answer 14

Right. [ )

Question 15

IQR

Answer 15

Inter quartile range Q3 - Q1

Question 16

Standard deviation

Answer 16

s = sqrt((1/(n-1))(sum(yi-y)^2))

Question 17

Sample variance

Answer 17

s^2

Question 18

Sum of differences

Answer 18

sum(yi-ybar)

Question 19

RV - Definition and common variable

Answer 19

Represents a random process (X)

Question 20

Realization - Definition and common variable

Answer 20

observed outcome of RV (x)

Question 21

Probability Distribution of X

Answer 21

describes values that X can take and the probability of each. ( Normally a table for discreet RV)

Question 22

Discrete RV - Definition and function

Answer 22

only certain values can be listed p(x)

Question 23

Two properties of discrete RV and variables

Answer 23

Mean(mu) and variance(sigma^2)

Question 24

Continuous RV- Definition and function

Answer 24

X takes values in a range, cannot list all of them. f(x)

Question 25

p.d.f - relates to… and symbol

Answer 25

probability density function f(x)

Question 26

Mean (RV)

Answer 26

mu(x) = E(x) = sum(xp(x))

Question 27

Variance (RV)

Answer 27

sigma^2 = VAR(X) = sum(((x-mu(x))^2)p(x))

Question 28

Binomial RV

Answer 28

n identical trials with 2 outcomes. Probability of each trial is (pi)

Question 29

Binomial RV - how to symbolize

Answer 29

X~Bin(n,(pi))

Question 30

Binomial RV - p.m.f

Answer 30

p(x) = ((n!)/(x!(n-x)!))((pi^x)((1-pi)^(n-x)))

Question 31

Binomial RV - mean

Answer 31

mu(x) = n(pi)

Question 32

Binomial RV - variance

Answer 32

sigma^2 = n(pi)(1-(pi))

Question 33

Normal RV - how to symbolize

Answer 33

X~N(mu,sigma^2)

Question 34

Normal RV - inflection points occur…

Answer 34

at mu +- sigma

Question 35

Normal RV - Area under f(x) between inflection points

Answer 35

0.68