**Due:** At the start of class on Thursday, September 1.
Please turn in a hard copy.

**Question 1** Download the data
`fertilizer_2000.RData`

from the course website to answer
this question (there is also a description file on the course
website).

How many observations does this data contain?

Data about what country is provided in the 21st row?

What is the average per capita GDP across all countries in the data?

What is the average precipitation among countries that have higher than average per capita GDP?

**Question 2** The Fibonacci sequence is the sequence of
numbers \(0,1,1,2,3,5,8,13,21,34,55,\ldots\) that
comes from starting with \(0\) and
\(1\) and where each subsequent number
is the sum of the previous two. For example, the 5 in the sequence comes
from adding 2 and 3; the 55 in the sequence comes from adding 21 and
34.

Write a function called

`fibonacci`

that takes in a number`n`

and computes the nth element in the Fibonacci sequence. For example`fibonacci(5)`

should return`3`

and`fibonacci(8)`

should return`13`

. Use your function to compute the 16th element of the Fibonacci sequence.Consider an alternative sequence where, starting with the third element, each element is computed as the sum of the previous two elements (the same as with the Fibonacci sequence) but where the first two elements can be arbitrary. Write a function

`alt_seq(a,b,n)`

where`a`

is the first element in the sequence,`b`

is the second element in the sequence, and`n`

is which element in the sequence to return. For example, if \(a=3\) and \(b=7\), then the sequence would be \(3,7,10,17,27,44,71,\ldots\) and`alt_seq(a=3,b=7,n=4) = 17`

. Use your function to compute the 16th element of the this alternative sequence for \(a=5\) and \(b=9\).