module 2

Question 1

what is a central tendency

Answer 1

a values/ # which best represents a data set ( a summary stat)

maybe a mean, median, or a mode

Question 2

what is variation within a sample

Answer 2

the spread of the data

note that greater variation in a sample causes the estimate of the data to the actual parameter to be less precise

Question 3

what is a mean

Answer 3

the arveage of all the values in a data set

Y-=x/n

best used with symmetrical data but is also used for ordinal data

Question 4

what is a median

Answer 4

the middle values of a data set

commonly used to asses sked data such as household income

commonly used to asses continuous data and ordinal data
NO NOMINAL DATA

note, if there is an odd # of variables there will be 1 median, but if there is an even there will be 2 medians

Question 5

what is a mode

Answer 5

the most commonly reoccurring value in a data set

commonly with nominal and categorical data!! possibly ordinal data

Question 6

when should each measurement of central tendency be used?

Answer 6

Mode: nominal scale (no order), ordinal scale, interval, and ratio
Mean: interval and ratio data
Median: ordinal, interval and ratio

Question 7

what is range

Answer 7

the difference between the 2 most extreme scores of a data set

Question 8

what is the standard deviation?

Answer 8

the values which take into account the spread of all data values in a data set

note that a smaller standard deviation allows for a more precise estimate

Question 9

what is meant by having skewed data

Answer 9

when the data results in an asymmetrical distribution