Answer:
k=2.5
Step-by-step explanation:
7.6/2 = 3.8
9.5/3.8 = 2.5
700 x .03 x 20 = 420
420 + 700
1120 is in the account after 20 years
He adds a higher number to the original summed number every time:
3(+2), 5(+3), 8(+5), 13(+8), 21(+13), 34
From +2 to +3 there is a difference of 1.
From +3 to +5 there is a difference of 2. Observe how the numbers increase
From +5 to +8 there is a difference of 3.
Etc...
Hope it helped,
Happy homework!