Question

Is the data set approximately periodic? If so, what are its period and amplitude?

Answer 1

From the data set shown, the data is periodic, this can be deduced by plot of the data.
This can be shown in the attached plot. From the plot we see that the period is 4 and the amplitude is about 25.
Hence the correct answer is:

Periodic with with a period of 4 and an amplitude of about 25 

Answer 2

Answer:

Option: c is the correct answer.

Periodic with a period of 4 and amplitude of about 25.

Step-by-step explanation:

We are given a data set as:

Day             1      2       3     4      5      6     7      8      9      10     11     12

Books       102   78    91    140   98    74   88   137  100    75    92  139

borrowed

We divide the data set into three parts as follows:

1)

Day                            1           2            3         4

Books Borrowed     102        78          91       140

2)

Day                            5           6            7         8

Books Borrowed      98         74          88       137

3)

Day                            9           10          11        12

Books Borrowed     100         75          92      139

As we see that the values repeat approximately after every 4 values.

This means that the period of the data set is: 4

Also the amplitude of the data set is the average of difference between the  maximum value and the minimum value.

1)

Amplitude=(140-78)/2=31

2)

Amplitude=(137-74)/2=31.5

3)

Amplitude=(139-75)/2=32

The most approximate answer is:

Amplitude= 25