Competency 18: Probability & Statistics

Question 1

Nominal data

Answer 1

counted data. Ex) # of students in a class who have cats, dogs, birds, fish, or no pets.

Question 2

Ordinal (or rank) data

Answer 2

gathered from surveys, particularly opinion surveys. Scales run from 1 to 5, 1 to 7, or some other odd #.

Question 3

Interval data

Answer 3

the measure of distance between data items. type of data teachers most often deal with in classroom. ex) grade distribution for test.

Question 4

mean

Answer 4

the arithmetic average of the data points and is found by summing all the data points & dividing by the total # of data points.

Question 5

Median

Answer 5

The point that separates the data points into two sections of equal size.

Question 6

Mode

Answer 6

The data point that occurs the most number of times in a set of data.

Question 7

Range

Answer 7

the difference between the largest value and the smallest value in the data.

Question 8

Interquartile Range

Answer 8

The difference between the upper quartile and lower quartile where the lower quartile is the median of the lower half of the sample data and the upper quartile is the median of the upper half of the sample data.

Question 9

Variance

Answer 9

the expected value of the square of the deviation of x from its own mean. to determine, find the difference between a data point and the mean of the data set and square the difference.

Question 10

Sample variance

Answer 10

The sum of squared deviation divided by n-1.

Question 11

Standard Deviation

Answer 11

the square root of the variance. shows how the data is distributed about the mean.