Test 2 Practice

What is this symbol? (σ)

• sigma: sample SD

• sigma: population mean

• sigma: sample mean

• sigma: population SD

What is this symbol? (X̄)

• data point in the population

• data point in the sample

• mean of the sample

• mean of the population

What is this symbol? (μ)

• mu: mean of the population

• mu: mean of the sample

• mu: mean of the population

• mu: SD of the population

In statistics we use alpha (α) for ...

• Reliability (Cronbach's Alpha)

• Type I Error

• All of the above

• probability cut off level

The standard deviation is a measure of ____ and is an example of ____ type of stat.

• central tendency/inferential

• variability/descriptive

• variability/inferential

• central tendency/decriptive

Hypothesis testing is an example of using _____ to ____ something about the ____.

• the sample/infer/the population

• the sample/describe/the population

• the population/describe/the sample

• the population/describe/the sample

How do you increase confidence intervals?

• bigger standard deviation

• smaller mean

• decrease the confidence level from 99 to 95

• increase the confidence level from 95 to 99

Type I error is

• Rejecting the research hypothesis when it is false

• Failing to reject a true null

• Failing to reject a true research hypothesis

• Rejecting the null when it is true

let's say the average score on Test 2 is 65. If you got a 56. A _____ standard deviation would put you closer to the mean and did "better" compared to the class? I want you to think about why.

• LOW for example: SD = 2

• HIGHER for example: SD = 10

What is the mean score equal to when you convert it to a Z (standard deviation)

• 0

• 1

• -1

• 0.5