Answer:
The BEST prediction for the number of days testing, for 2nd grade is:
25
Explanation:
From the bar graph we observe that the grades first increases and then decreases and hence, the bar graph is symmetric about the 3 rd grade.
Also, the value to the left are slightly higher then those on the right.
and hence the number of days would be slightly higher than 25.
Hence, the value will be close to 25.