Answer:
1.46
Step-by-step explanation:
First find the the mean score before he made a 90.

Now add the score of 90 and calculate.

Subtract the two scores.

His mean test score increased by 1.46.
= 30%
= 0.3
= 3/10
Hope this helps.
Answer:
Their is a different question in the pic then the writing?
Answer:
1/170
Step-by-step explanation:
divide 12 by 2040