Week 10 - Descriptive Statistics

Question 1

identify the different types of graphic representations of data

Answer 1

Bar charts (bars don’t touch)
Histograms (bars touch)
Scatterplots (shows relationship/correlation)
Line graphs (helps interpret interactions between quantitative variables)

Question 2

explain the different measures of central tendency

Answer 2

Mean - average of data set.
Median - the middle number (if all values numerically sorted)
Mode - Most frequent/common number in all data set (highest bar in histogram)

Question 3

describe the different measures of variability.

Answer 3

Range = largest score - smallest score
-the range of the data dispersion.

Variance - the average deviation of data values from their mean in squared units. Var = (each score-mean)squared > total those numbers and divide by how many numbers in the data set.

Standard Deviation = Square root of the variance. How far we are from the mean on average. The larger the number the greater the data spread.

Z-Score - specifies the precise location of each x value within the distribution.

Question 4

Describe the 68-95-99.7 rule

Answer 4

68% of scores will fall within 1 standard deviation of the mean
95% will fall within 2 standard deviations
99.7% will fall within 3 standard deviations