Milly and Chocolates

3.2

191 votes
Ready, Approved, Easy, Probability and Statistics
Problem

Milly loves to eat chocolates. She buys only those food items which contain some amount or percentage of chocolate in it. She has purchased N such food items and now she is planning to make a new food item by her own. She will take equal proportions of all of these N food items and mix them. Now she is confused about the percentage of chocolate that this new food item will have. Since she is busy in eating the chocolates so you have to help her in this task.

Input

First line of the input will contain T (no. of test cases). Every test case will contain two lines. First line will contain N (no. of food items) and the second line will contain N space separated Pi values denoting the percentage of chocolate in ith food item.

Output

For every test case, print the percentage of chocolate that will be present in the new food item.

Note : Your answer should be exactly upto 8 decimal places which means that if your answer is 2.357 then you have to print 2.35700000 or if your answer is 2.66666666 .... then you have to print 2.66666667

Constraints

1 <= T <= 5
1 <= N <= 5*105
0 <= Pi <= 100

Time Limit: 1
Memory Limit: 256
Source Limit:
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