L14, L16- Statistics and Distribution

Question 1

describe general addition rule (of probabilities)

Answer 1

P(A or B) = P(A) + P(B) - P(A and B)
OR (if A/B are mutually exclusive)
P(A or B) = P(A) + P(B)

Question 2

describe multiplication rule (of probabilities)

Answer 2

P(A and B) = P(A given B)P(B)
OR (if A/B are independent)
P(A and B) = P(A)P(B)

Question 3

list types of categorical data

Answer 3

• nominal data

- ordinal data

Question 4

list types of continuous data

Answer 4

• interval data (equal distance between data points)

- ratio data (interval data with a true 0)

Question 5

explains the two basic descriptions for numerical data

Answer 5

Measures of Central Tendency: continuous data, mean, median, mode

Measures of Variation: spread of data / distribution

Question 6

(T/F) every dataset has one mode

Answer 6

F- there can be zero, one, or multiple modes of a dataset

Question 7

list the measures of variation

Answer 7

• range
• variance
• standard deviation (sqrt(var))
• quartiles

Question 8

define IQR

Answer 8

inter quartile range (Q3 - Q1)

Question 9

differentiate between Probability Density and Probability Distribution

Answer 9

Density- for continuous variables, defined as area under the curve (integral)

Distribution- for categorical variables, defined as sum of all possible outcomes

Question 10

define µ and x̅ (in statistics)

Answer 10

µ- population mean

x̅- sample mean

Question 11

define Standard Normal Distribution

Answer 11

µ = 0
σ = 1

above µ has +Z-values, below has -Z values

area under the curve = probability

Question 12

what is the formula to convert normal distribution to a standard normal distribution

Answer 12

Z = (X - µ) / σ

Question 13

to assure normality of data (normality assumption), (1) and (2) are used to confirm

Answer 13

1- histogram

2- boxplot