user: I've got this investment sitting at $5000 with an annual interest rate of 5%. I'm planning to let it grow over the next 10 years without making any additional contributions. I need to calculate what this will amount to at the end of the 10-year period. Once I have that future value, I'm curious about how it would perform in a hypothetical scenario where the returns follow the Fibonacci sequence, so I'd like to know what the 15th number in that sequence is. And lastly, I have this list of numbers: 45, 23, 67, 89, 12, 34, 56, 78. I need them sorted, but in descending order. Can we get started on these calculations?

Available functions:
name: calculate_future_value
description: Calculates the future value of an investment.
parameters: type: dict
properties: present_value: type: float
description: The present value of the investment, in dollars.
interest_rate: type: float
description: The interest rate of the investment, ranging from 0 to 1.
periods: type: integer
description: The number of periods, in years.
required: present_value
interest_rate
periods
name: get_fibonacci_sequence
description: Calculates the n numbers of the Fibonacci.
parameters: type: dict
properties: n: type: integer
description: The number of Fibonacci numbers to calculate.
required: n
name: get_fibonacci_number
description: Calculates the nth Fibonacci number in the sequence where the sequence starts with 0 followed by 1, and each subsequent number is the sum of the previous two.
parameters: type: dict
required: n
properties: n: type: integer
description: The position of the Fibonacci number to calculate. This position must be a positive integer.
name: sort_array
description: Sorts an array of numbers.
parameters: type: dict
properties: array: type: array
items: type: float
description: The array of numbers.
reverse: type: boolean
description: Whether to sort the array in reverse order, i.e., descending order.
default: no
required: array

Ground truth function call(s):
calculate_future_value(present_value=5000, interest_rate=0.05, periods=10)
get_fibonacci_number(n=15)
sort_array(array=[45, 23, 67, 89, 12, 34, 56, 78], reverse=True)