Adding probabilities when you should multiply

"The AND/OR Mixup"

Probability & Statistics

Assuming correlation means causation

"The Causation Confusion"

Probability & Statistics

Finding median without ordering data first

"The Middle Muddle"

Probability & Statistics

Giving probability greater than 1

"The Impossible Probability"

Probability & Statistics

Plotting cumulative frequency at class midpoints

"The Midpoint Mistake"

Probability & Statistics

Using frequency for the height instead of frequency density H

"The Height Mistake"

Probability & Statistics

Averaging the values column instead of using frequencies

"The Frequency Forgetter"

Probability & Statistics

Not changing fractions for without replacement

"The Replacement Forget"

Probability & Statistics

Reading quartiles at wrong cumulative frequency values

"The Quartile Confusion"

Probability & Statistics

Reading the height instead of calculating the area H

"The Reading Error"

Probability & Statistics

Treating extrapolation as reliable

"The Extrapolation Overreach"

Probability & Statistics

Using wrong total for denominator

"The Total Trouble"

Probability & Statistics

Calculating the wrong class width H

"The Width Blunder"

Probability & Statistics

Comparing box plots without using values

"The Vague Comparison"

Probability & Statistics

Drawing line of best fit through all points

"The Connect-the-Dots Error"

Probability & Statistics

Subtracting the wrong value for complementary events

"The Complement Confusion"

Probability & Statistics

Tree diagram branches not summing to 1

"The Branch Blunder"

Probability & Statistics

Using class boundaries instead of midpoints

"The Boundary Blunder"

Probability & Statistics

Adding highest and lowest instead of subtracting

"The Range Reversal"

Probability & Statistics

Leaving gaps between histogram bars H

"The Gap Problem"

Probability & Statistics

Mixing up percentage and decimal forms

"The Percentage Pickle"

Probability & Statistics

Confusing expected frequency with probability

"The Expected Error"

Probability & Statistics

Giving the position as the answer instead of the value

"The Position Problem"

Probability & Statistics

Assuming outcomes are equally likely when they are not

"The Fair Fallacy"

Probability & Statistics