Averages from Tables Flashcards

All 6 cards in this deck

In a frequency table of discrete data, how do you find the mode?

Write down the data value (not the frequency) with the highest frequency.

True or false? In a frequency table, if the highest frequency is 15 then the mode is 15.

False. The mode is the data value that has that frequency, not the frequency itself.

What formula gives the mean from a frequency table?

Mean $=\dfrac{\Sigma fx}{\Sigma f}$

What are the steps to find the mean from a frequency table?

e.g. value $1$ (frequency $2$), value $4$ (frequency $3$)

1. Multiply each value by its frequency: $1\times2=2$, $4\times3=12$
2. Add them: $\Sigma fx = 14$; add frequencies: $\Sigma f = 5$
3. Divide: $14\div5=2.8$

How do you find the position of the median from a frequency table?

e.g. total frequency $\Sigma f = 19$

Work out $\dfrac{\Sigma f + 1}{2}$ to get the position, then count up the frequencies to that position.
$(19+1)\div2 = 10$th value

True or false? To find the mean from a frequency table you divide $\Sigma fx$ by the number of rows in the table.

False. You divide by $\Sigma f$, the total frequency.