Module 7 Practice Questions (2)

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean. It is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

How do you calculate a z-score for Sarah's hourly wage of $30, given a mean of $35 and a standard deviation of $5?

Back

Z-score = (30 - 35) / 5 = -1.0.

Front

What is a random variable?

Back

A random variable is a variable whose possible values are numerical outcomes of a random phenomenon.

Front

What are the possible values for a random variable Y that can take values from 1 to 6 if the requirement is at least 4?

Back

The possible values are 4, 5, and 6.

Front

What is a probability distribution?

Back

A probability distribution describes how the probabilities are distributed over the values of the random variable.

Front

How do you find the probability of at least two sales in an hour for a given probability distribution?

Back

Sum the probabilities of making 2 or more sales.

Front

What is the mean of a probability distribution?

Back

The mean is the expected value, calculated as the sum of all possible values multiplied by their probabilities.

Front

How do you calculate the mean of Y given its probability distribution?

Back

Mean = Σ (value * probability) for all values.

Front

What does it mean if the probability of an event is 0.85?

Back

It means there is an 85% chance that the event will occur.

Front

What is the probability of at least one defect in a randomly chosen hour if the probability of no defects is 0.15?

Back

Probability of at least one defect = 1 - Probability of no defects = 1 - 0.15 = 0.85.