BIOL101A: Ex. 2 Graphs and Measurements

measurement

description of a phenomenon in precise terms which then can be handled objectively

systolic pressure

equal to the maximum pressure recorded in an artery

diastolic pressure

the minimum pressure recorded in an artery 

waist-to-hip ratio

estimates belly fat

normal distribution

the definite pattern with most of the values clustered toward the middle of the range and very few values at the extreme edges of the range

• described the variation in a large number of phenomena, biological and non-biological

central tendency

the idea that there is a tendency for values to group around a central value

distribution

a certain degree of variability or spread away from this central value

mean

the average value obtained by dividing the sum of a sample of quantities by the total number of quantities added 

median

another measure of central tendency that is the middle-most value of a list of values comprising the data set

• 4,9,10,10,13,24,22,34

  • 13 —> middle most

mode

the value in a data set that occurs most frequently

standard deviation

measure of variability relative to the mean 

• Xi - avg = the difference of each value from the mean 

• N = total number of individual measurements (same size) 

• can be used to predict the number of measurements which should fall within any given interval centered on the mean 

causality

demonstrated by altering one variable (IV) in the system experimentally and then observe whether a corresponding change takes place in the other variable (DV) 

statistical correlation

measures the strength and direction of a linear relationship between two variables