<span>After 1 hour, the diving bell was -1/2 mile relative to sea level.
Since the rate of decent is constant, we can use two ratios to represent the depth at 2 different times. To make things easier to write, I'll use decimals to represent time and depth.
-.75 / 1.5 = x / 1
Now solve for x
-0.5 = x
So after 1 hour, the diving bell was -1/2 mile relative to sea level.</span>
My understanding is that when the power is a negative number, move it to the denominator and change it to positive.
In this case, the base is y, the power is -3
y^(-3)=1/(y^3)
Given:
The price of bananas can be determined by the equation P=0.25n, where P is the price and n is the number of bananas.
To find:
The constant of proportionality
Solution:
We have,
...(i)
where P is the price and n is the number of bananas.
Price P is directly proportional to the number of bananas. So,

...(ii)
Where, k is the constant of proportionality.
On comparing (i) and (ii), we get

Therefore, the constant of proportionality is 0.25.
I believe the answer is between 90-100.
Hopes this helps