Python and Probability Midterm Flashcards (Midterm 2)

What does the if-statement do?

It controls execution flow, running a code block if and only if the conditional is true

Which code runs when the conditional is false?

The else statement is used to run a block of code only when the preceding if conditional is false

Six comparison operators for Python conditionals?

==, >, >=, <, <=, and !=

Why use parentheses in complex Pandas conditionals?

Parentheses ensure the correct order of evaluation, as Python defaults to combining ANDs (&) before ORs (|)

Keyword to define a new function?

The Python keyword def is used to define a new function

What are variable placeholders in a function called?

These placeholders are called arguments (or parameters)

Make a function argument optional, how?

By setting a default argument value in the function definition ( e.g., def function(arg = value): )

What does the term for standard deviation mean?

Standard Units or Z scores, which indicate how many standard deviations a value is from the average

Function for area left of Z-score?

norm.cdf(z_score) (cumulative distribution function) from typing "from scipy.stats import norm"  (norm.ppf for percentages)

Standard normal curve's mean value?

The standard normal curve is centered at 0 and has an average (mean) of 0

Define probability or chance.

The expected percentage of times a certain outcome occurs when a process is repeated over and over

Define event's sample space.

The set of all possible outcomes of that event

Define the probability's complement rule.

P(event)= 1 minus the probability it does not happen

Addition Rule for non-mutually exclusive events?

P(A or B)=P(A)+P(B)−P(A and B) (The subtraction avoids double counting)

Mutually exclusive events: what is P(A and B)?

If events are mutually exclusive (Special Case), P(A and B) is 0

Multiplication Rule for independent events?

P(A and B)=P(A)×P(B)

Multiplication Rule for dependent events?

P(A and B)=P(A)×P(B∣A) (where P(B∣A) is the conditional probability)

Define conditional probability P(B | A).

The probability that event B will occur given that event A has already occurred

Bayes' Rule expresses what probability?

P(B|A)=P(A|B)×(P(B)/P(A))