MEDIAN for GROUPED DATA

MEDIAN for GROUPED DATA

by Ph-USA Guru

WHAT IS MEDIAN?

• It was pointed out that the arithmetic mean is often not representative of data with extreme values. 

• It is a useful measure when we encounter data with an extreme value.

• The midpoint of the values after all observations have been ordered from the smallest to the largest, or from largest to smallest.

WHAT ARE THE PROPERTIES OF MEDIAN?

• 1.The median is a unique value, that is, like the mean, there is only one median for a set of data.

• It is not influenced by extremely large or small values.

• It can be computed for ratio level, interval level, and ordinal-level data.

• Fifty percent (50%) of the observations are greater that the median and 50% of the observations are less than the median.

Multiple Choice

What is median?

• It is a useful measure when we encounter data with an most value.

• It is influenced by extremely large or small values.

• It is the middle value.

• The midpoint of the values after all observations have been ordered from the smallest to the largest, or from largest to smallest.

Multiple Select

WHAT IS CUMULATIVE FREQUENCY?

• Cumulative frequency is used to determine the number of observations that lie above (or below) a particular value in a data set.

• The cumulative frequency is calculated using a frequency distribution table, which can be constructed from stem and leaf plots or directly from the data.

• The cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors.

• The last value will always be equal to the total for all observations, since all frequencies will already have been added to the previous total.

In finding the MEDIAN for GROUPED DATA, we need a column for CUMULATIVE FREQUENCY.

Construct a CUMULATIVE FREQUENCY column

• What is the first frequency?

• Add all the frequencies starting from the first.

How to construct a cumulative frequency?

• Please copy the table.

• 
  

Find the MEDIAN CLASS?

• Divide n by 2.

• The median class is the class interval that is equal to n/2 found on cumulative frequency column.

• If there's no equal, take the number greater than n/2 on cumulative frequency column.

Multiple Choice

How to get the median class?

• First, divide the frequency by 2 or f/2.

• First, divide the total frequency by 2 or n/2.

• First, multiply the frequency by 2 or f x 2.

• First, multiply the total frequency by 2 or n x 2.

Multiple Choice

After dividing n by 2 (n/2), locate the median class. What is the median class?

• The median class is the class which is equal to n/2 found on cumulative frequency column.

• The median class is n/2.

• The median class found on cumulative frequency column.

• The median class is in the middle.

Multiple Choice

How do we find median If there's no number equal to n/2?

• Get the number above the cumulative frequency column.

• Get the number greater than n/2 on cumulative frequency column.

• Get the number greater than cumulative frequency.

• All of the above.

Multiple Choice

How to find the lower boundary?

• Lower Limit plus 0.5 or LL + 0.5.

• Lower Limit minus 0.5 or LL - 0.5.

• Lower Limit times 0.5 or LL x 0.5.

• Lower Limit divide 0.5 or LL/0.5.

Formula in finding the median for grouped data.

• Please COPY!!!

Multiple Choice

What is LBmc?

• Lower Boundary of median column.

• Lower Boundary of the mean class.

• Lower Boundary of the median class.

• Lower Boundary of the median column.

Open Ended

What is Md?

Multiple Choice

What is fmc?

• Frequency of the mean class.

• Frequency of the mean column.

• Frequency of the median class.

• Frequency of the median column.

Multiple Choice

What is i?

• Interval

• Internet

• Internal

• Interactive

Multiple Select

How to find the interval?

• Upper Limit + Lower Limit - 1

• Upper Limit – Lower Limit - 1

• Upper Limit + Lower Limit + 1

• Upper Limit – Lower Limit + 1

Give the values of n/2, LBmc, Less than frequency and interval.

• Please copy.

The MEDIAN.

• COPY!!!

• COPY!!!

Poll

Did you copy the notes for your reference?

• No

• Yes

Poll

Do you have any question(s) or clarification(s)

• No, I understand and ready for individual practice.

• Yes, I will type my questions in the chat box.

• Yes, I will unmute myself and ask.

• Yes, I need videos or powerpoint for this.