Statistics Section 2 Review Guide

Which is the formula to calculate z- score?

• z = (x - μ) / σ

• z = (x + μ) / σ

• z = (x + μ) / M

In calculating z- score, using: z = (x + μ) / σ, x represents:

• the data point

• mean

• standard deviation

In calculating z- score, using: z = (x + μ) / σ, σ represents:

• the mean

• population standard deviation

• the value

The ____________ indicates how many standard deviations a data point is away from the mean. 

• z-score

• mean

• standard deviation

• A child is at the 75th percentile for height:

• • This means 75% of children their age are shorter than them. 

• • This means 75% of children their age are taller than them. 

• • This means they are taller than 25% of children their age

• • This means they are more advanced than 25% of children their age

The median can also be refered to as...

• Q2

• Q1

• Q4

• Q3

Q3 - Q1 would give us the (a)  

If your data set is normal, or symmetric the best measure to use would be

• mean/ standard deviation

• median/ IQR

Represents the average value of a data set, most useful for symmetric distributions. 

(a)  

Represents the middle value of a data set, better for skewed distributions or data with outliers. 

(a)