The document provides a detailed guide on creating frequency distributions using Excel, including sorting data, calculating class widths, and determining class frequencies and midpoints. It explains how to compute relative and cumulative frequencies step-by-step, ensuring that the total of frequency matches the data points. The author emphasizes the importance of accuracy and encourages helping others in learning.

1. HELP ON FREQUENCY
DISTRIBUTIONS
B Heard
Not to be posted in a
classroom or used without
my permission. Students
can download one copy for
their own person use.

2. HELP ON FREQUENCY
DISTRIBUTIONS
Let’s say we were given one like this…

3. HELP ON FREQUENCY
DISTRIBUTIONS
First thing I would do is copy the data
Copy data

4. HELP ON FREQUENCY
DISTRIBUTIONS
Remember I noted that Minitab doesn’t
do these, so I paste into Excel
Just use
“Ctrl V” or
Paste

5. HELP ON FREQUENCY
DISTRIBUTIONS
I then clicked on Column A, Selected Data
from the top tabs of Excel, then chose
Sort and sorted from smallest to largest

6. HELP ON FREQUENCY
DISTRIBUTIONS
Now that they are sorted, I can easily see
the minimum and maximum values (30 is the
Smallest, 548 is the Largest)

7. HELP ON FREQUENCY
DISTRIBUTIONS
The problem asked me to use “6 classes”
So I first Subtract the Minimum Value from the Maximum Value
548-30 = 518
I now divide this by the desired number of classes
518/6 = 86.3, and round up to the next whole integer
So my class width will be “87”

8. HELP ON FREQUENCY
DISTRIBUTIONS
Start with my minimum value
30
Add class width to 30 to get 30+87 =117
Add class width to 117 to get 117+87 = 204
Add class width to 204 to get 204+87 = 291
Add class width to 291 to get 291+87 = 378
Add class width to 378 to get 378+87 = 465
This gives me the
lower limits of my 6
classes

9. HELP ON FREQUENCY
DISTRIBUTIONS
So I will have
30 - 116
117 - 203
204 - 290
291 - 377
378 - 464
465 - 551 (I got the 551 by adding the class width “87” to the
previous class’ upper limit “464+87 = 551)
Now I have my 6
classes and I will
need to figure out
how many data
points are in each
one.

10. HELP ON FREQUENCY
DISTRIBUTIONS
I simply count from my ordered Excel, I color coded to make it easier
to see
Class Frequency
30 – 116 5
117 – 203 3
204 – 290 2
291 – 377 6
378 – 464 4
465 – 551 9

11. HELP ON FREQUENCY
DISTRIBUTIONS
Now I need to get the Midpoints
Class Frequency Midpoint
30 – 116 5 73
117 – 203 3 160
204 – 290 2 247
291 – 377 6 334
378 – 464 4 421
465 – 551 9 508
I get the Midpoint by adding the
lower and upper limits and dividing
by 2. For example on the first one
(30+116)/2 = 73
Don’t forget to add the two together
before dividing

12. HELP ON FREQUENCY
DISTRIBUTIONS
Now I need to get the Midpoints
Class Frequency Midpoint
30 – 116 5 73
117 – 203 3 160
204 – 290 2 247
291 – 377 6 334
378 – 464 4 421
465 – 551 9 508
I get the Midpoint by adding the
lower and upper limits and dividing
by 2. For example on the first one
(30+116)/2 = 73
Don’t forget to add the two together
before dividing

13. HELP ON FREQUENCY
DISTRIBUTIONS
In getting your Relative Frequency, you first need to total your frequencies
Class Frequency Midpoint
30 – 116 5 73
117 – 203 3 160
204 – 290 2 247
291 – 377 6 334
378 – 464 4 421
465 – 551 9 508
29
Your total of your frequency column
should be equal to the total number
of data points you had. In Excel, it
was easy to see we had “29” so we
are good.

14. HELP ON FREQUENCY
DISTRIBUTIONS
To get your Relative Frequencies, you simply divide your frequency by your
total
Class Frequency Midpoint Rel. Frequency
30 – 116 5 73 0.172
117 – 203 3 160 0.103
204 – 290 2 247 0.069
291 – 377 6 334 0.207
378 – 464 4 421 0.138
465 – 551 9 508 0.310
29
Simply the
decimal form of
the Frequency
divided by the
total. For
example the first
one would be
5/29 = 0.172
rounded to three
decimal places.
The last one
would be 9/29 =
0.310 rounded to
three decimal
places. Round to
the number of
decimals
specified in the

15. HELP ON FREQUENCY
DISTRIBUTIONS
Finally, we need to get the cumulative frequencies…
Class Frequency Midpoint Rel. Frequency Cumulative
Freq.
30 – 116 5 73 0.172 5
117 – 203 3 160 0.103 8 (5+3)
204 – 290 2 247 0.069 10 (5+3+2)
291 – 377 6 334 0.207 16 (5+3+2+6)
378 – 464 4 421 0.138 20 and so on
465 – 551 9 508 0.310 29
29
With your
cumulative
frequencies, your
first one should
match the
frequency of your
first class, then
for the second,
just add the
frequency of the
first and second
classes. Continue
until the last
class. Your last
cumulative
frequency should
match with your
sum or total of

16. HELP ON FREQUENCY
DISTRIBUTIONS
Now we have it!!!
Class Frequency Midpoint Rel. Frequency
Cumulative Freq.
30 – 116 5 73 0.172 5
117 – 203 3 160 0.103 8
204 – 290 2 247 0.069 10
291 – 377 6 334 0.207 16
378 – 464 4 421 0.138 20
465 – 551 9 508 0.310 29

17. HELP ON FREQUENCY
DISTRIBUTIONS
They ask which class has the greatest frequency… OBVIOUS 465-551
Class Frequency Midpoint Rel. Frequency
Cumulative Freq.
30 – 116 5 73 0.172 5
117 – 203 3 160 0.103 8
204 – 290 2 247 0.069 10
291 – 377 6 334 0.207 16
378 – 464 4 421 0.138 20
465 – 551 9 508 0.310 29

18. HELP ON FREQUENCY
DISTRIBUTIONS
They ask which class has the least frequency… OBVIOUS 204-290
Class Frequency Midpoint Rel. Frequency
Cumulative Freq.
30 – 116 5 73 0.172 5
117 – 203 3 160 0.103 8
204 – 290 2 247 0.069 10
291 – 377 6 334 0.207 16
378 – 464 4 421 0.138 20
465 – 551 9 508 0.310 29

19. HELP ON FREQUENCY
DISTRIBUTIONS
I hope this helped you…
I put a lot of time in it just for you…
To pay me back, help a child with math or anything else…
If you see any errors, please let me know in the Stat Cave.