Module 4

Question 1

What are the basics of a Probability Density Function for Continuous Random Variables?

Answer 1

• Probabilities are provided by the area under the graph of f(x), but it’s the probability that x assumes a value in that interval, rather than a specific value.
• The area under a particular point on a graph is basically zero, so the probability of any particular value is also zero.

Question 2

What’s a Uniform Probability Distribution?

Answer 2

• any point during a given interval is equally likely
• sum of all probabilities = 1

Question 3

What are the basics of a Normal Probability Distribution and what’s it good for?

Answer 3

• good for heights, weights, test scores, scientific measurements, rainfall, etc.
• symmetrical: mean = median = mode

Question 4

What’s the standard normal distribution?

Answer 4

• Mean = 0
• SD = 1
• Normal random variable = Z

Question 5

What’s a Poisson distribution good for estimating?

Answer 5

Number of occurrences per interval.

Question 6

What’s an Exponential distribution good for estimating?

Answer 6

Length of interval between occurrences.

Question 7

What is a continuity correction factor?

Answer 7

If using a normal curve to approximate discrete probabilities, add a continuity correction factor: a value of 0.5 that is added to or subtracted from the value of x when the continuous normal distribution is used to approximate the discrete binomial distribution.
I.e. P(x=12)&raquo_space;> P(11.5</= x </= 12.5)