Answer: Histogram of 30-40 becomes slightly low and histogram of 40-50 becomes slightly high.
Explanation:
Since we have given that
C.I. Frequency
10-20 1
20-30 4
30-40 15
40-50 14
If one score of 39 changed to 40.
Then it comes under class interval of 40-50
so, frequency under 30-40 becomes 14.
frequency under 40-50 becomes 15.
So, Histogram of 30-40 becomes slightly low and histogram of 40-50 becomes slightly high.