Answer:
Rhombus
Step-by-step explanation:
B. would be the correct choice here
Solution :
Group Before After
Mean 693.75 743.75
Sd 155.37 143.92
SEM 54.93 50.88
n 8 8
Null hypothesis : The preparation course not effective.

Alternative hypothesis : The preparation course is effective in improving the exam scores.
(after - before)
If you're talking about the ratio 10:4, you can decrease it by dividing both numbers by 2.
10:4=5:2
The ratio decreases to 5:2