Week 2

Question 1

What is univariate vs. bivariate?

Answer 1

Univariate - one variable at a time

bivariate - more then one varable

Question 2

When do you use a histogram vs. bar graph?

Answer 2

Histogram is for continuous data, bar graph is for categorical

Question 3

Which way is a negatively skewed distribution leaning?

Answer 3

Tail to the left, hump to the right

Question 4

What do many statistical techniques assume?

Answer 4

Normal distribution

Question 5

Why look at distribution?

Answer 5

• Screening for outliers
• Better descriptive statistics
• Choose the best inferential statistics

Question 6

What is better descriptive statistics if distribution is skewed

Answer 6

-Median and range over mean and standard deviation

Question 7

What is the measure of central tendency?

Answer 7

• Single score that defines the centre of a distribution

- A single score that is most representative of the entire distribution

Question 8

What is the mean?

Answer 8

Math average

Question 9

What is the median?

Answer 9

Score that divides distribution exactly in half

Question 10

What is the mode?

Answer 10

Most frequent score

Question 11

Describe variability?

Answer 11

• Describes the distribution (clustered or spread)
• Measures how well an individual score represents the entire distribution
• Provides information about how much error to expect if using a sample to treat the population

Question 12

Variability Measures

Answer 12

Range- difference between maximum and minimum score
Interquartile Range - 25th and 75th percentile
-Deviation scores - difference between each score and the mean
Variance- Average of the squared deviation scores
Standard Deviation - square root of variance