Answer:
Common difference(d) 
(21) -10 -548
(22) -7 -323
(23) 10 547
(24) -100 -5118
Step-by-step explanation:
Let the common difference be denoted by 'd'.
Also the nth difference of an arithmetic sequence is given by: 
(21)
We are given a recursive formula as:

The first term is given by:

The common difference for an arithmetic sequence is given by:

Hence, here we have the common difference as:

The nth term of an arithmetic sequence is given by:

Here
and
.
Hence, 
Hence, 
(22)


The common difference for an arithmetic sequence is given by:

Hence, here we have the common difference as:

Here
and
.
Hence, 
Hence, 
(23)


The common difference for an arithmetic sequence is given by:

Hence, here we have the common difference as:

Here
and
.
Hence, 
Hence, 
(24)


The common difference for an arithmetic sequence is given by:

Hence, here we have the common difference as:

Here
and
.
Hence, 
Hence, 
It’s 4/25 because 2/5 times 2/5 the numerator is 2 times 2 which is four and the denominator is 5 times 5 which is 25
Step-by-step explanation:
A bar graph serves to visibly represent the frequency of a series of events.
To create a bar graph you can draw on the horizontal axis, each one of the events, and on the axis to verticate the frequency of occurrence.
For this case the possible events are the values from 1 to 5 of the numbered sequence
1 2 3 4 5
The frequency for each number is
4 6 2 6 2.
With these values, a bar graph was made in excel, which is shown in the attached image.
There it is observed that the events with greater frequency are the 4 and the 2.