Module 2 - Probability: Concepts & Distributions

Question 1

Normal Distribution

Answer 1

• Bell curve
• Bigger values in the middle
• Sides are mirror images

Question 2

Histogram

Answer 2

Frequency diagram that shows the distribution of the results

Question 3

n

Answer 3

-Total number in sample

Question 4

Range

Answer 4

• The difference between the largest and smallest observation values
• Measures variability & shows how spread the data is

Question 5

Median

Answer 5

• Splits values into 2 groups when they are ordered lowest to highest
• If the number of values is even it’s the midpoint between to 2 middle values

Question 6

Mode

Answer 6

The value that occurs most frequently

Question 7

Mean

Answer 7

Average

Question 8

When the data has a symmetrical distribution…

Answer 8

The mean, the mode, & the median are the same

Question 9

In skewed distributions

Answer 9

• The mean lies toward the direction of the skew

- The mean is between the median and the tail

Question 10

Weighted average

Answer 10

The mean when you combine 2 different samples to evaluate the same variable

Question 11

Bimodal frequency distribution

Answer 11

Distribution has 2 distinct mounds in the distribution

Question 12

Deviations

Answer 12

• The difference between any observed value & the mean

- Broken into sections of equal distance from the mean

Question 13

Variance

Answer 13

Average of the squared deviations

Question 14

Empirical Rule

Answer 14

If the histogram of the data is approximately bell shaped:

• 68% w/in 1 SD
• 95% w/in 2 SD
• 99% w/in 3 SD