Write a function in python which takes in a dictionary, $`$abcb$\_$rates$`,$ and the amount of money to be deposited. The function should return the effective interest rate, also in percentage points. It is guaranteed that there are no gaps within the range of deposits, and that the promotional interest rates being applied starts from $$0.$ Once the amount deposited is above the range the reaming amount will be charged $0\mathrm{.}05\%$

For Example:

abcb$\_$rates $=\{$

$\text{'}$$$0-$ $$10000\text{'}$: $3\mathrm{.}00,$

$\text{'}$$$10000-$ $$30000\text{'}$: $4\mathrm{.}00,$

$\}$

calculate$($abcb$\_$rates, $40000)$

Expected output:

$2\mathrm{.}7625$

Explanation:

The value is gotten via $10000/40000*3\mathrm{.}00+20000/40000*4\mathrm{.}00+10000/40000*0\mathrm{.}05.$

The first $$10000$ is under $3\%$ interest, next $$20000($$$30000-$ $$10000)$ is under $4\%,$ and the last $$10000($$$40000-$ $$30000)$ is under $0\mathrm{.}05\%$ interest.