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Flashcards in Chapter 3 Deck (21):

Central Tendency

Where most of the scores are, which most closely represents the entire set


What is the definition for mean?

The average


What is the symbol for mean?

"Mew" looks kinda like a u or m. Also the symbol for micro.


How do you calculate mean?


The sum of all the raw scores divided by the number of raw scores.


What is the definition of a weighted mean?

Combo of multiple samples or populations' means


How do you calculate weighted mean if the n value for both groups are identical?

Mw= (M1 + M2)/2


How do you calculate a weighted mean if the n value for the groups are not identical?

Mw= (€X1+€X2)/(n1+n2)


If you change value of scores, what will happen to the mean?

Mean ALWAYS changed


What happens to the mean if you add or subtract a score?

Mean SOMETIMES changes.

If the number added or subtracted is identical to the mean, it will not affect the mean. If it's even slightly different from the previous mean, it will change.


What will happen if you add or subtract a constant for each score?

The mean will follow this trend.

Ex. If you add ten to every score, the mean will go up by ten.


What happens to the mean if you multiply or divide the scores by a constant?

The mean will follow the trend of the constant.

Ex. If scores are multiplied by ten, the mean will be multiplied by ten.


What does median mean?

The middle raw score when scores are put in numerical order.


How do you solve for median?

Arrange all raw scores from least to greatest and find the number in the middle. If there are two numbers in the middle, average out those numbers. The solution is the median.


What is the definition of mode?

The most frequent score


What's the definition of bimodal?

When there are two numbers that occur the most with the same frequency. Meaning two modes.


What is multimodal?

When there are three or more equal modes with the same frequency.


What is a major mode?

In a situation where two numbers stand out and need to both be represented, the one with the greater frequency is a major mode.


What is the definition of minor mode?

In a situation where two numbers have frequencies that stand out among a data set, and you want both represented, the number with the lower frequency is the minor mode.


What is the standard for central tendency? Mean, median, or mode?



When is it best to use median?

Outlier or skewed distribution Undetermined value
Open ended categories
Ordinal scale


When to use the mode?

Data from nominal scale
Discrete variables (kids)
Describing shape