Day 0: Mean, Median, and Mode

 
Objective

In this challenge, we practice calculating the mean, median, and mode. Check out the Tutorial tab for learning materials and an instructional video!

Task
Given an array, , of  integers, calculate and print the respective mean, median, and mode on separate lines. If your array contains more than one modal value, choose the numerically smallest one.

Note: Other than the modal value (which will always be an integer), your answers should be in decimal form, rounded to a scale of  decimal place (i.e., ,  format).

Input Format

The first line contains an integer, , denoting the number of elements in the array.
The second line contains  space-separated integers describing the array's elements.

Constraints

• , where  is the  element of the array.

Output Format

Print  lines of output in the following order:

1. Print the mean on a new line, to a scale of  decimal place (i.e., , ).
2. Print the median on a new line, to a scale of  decimal place (i.e., , ).
3. Print the mode on a new line; if more than one such value exists, print the numerically smallest one.

Sample Input

10
64630 11735 14216 99233 14470 4978 73429 38120 51135 67060

Sample Output

43900.6
44627.5
4978

Explanation

Mean:
We sum all  elements in the array, divide the sum by , and print our result on a new line.

Median:
To calculate the median, we need the elements of the array to be sorted in either non-increasing or non-decreasing order. The sorted array . We then average the two middle elements:

and print our result on a new line.

Mode:
We can find the number of occurrences of all the elements in the array:

 4978 : 1
11735 : 1
14216 : 1
14470 : 1
38120 : 1
51135 : 1
64630 : 1
67060 : 1
73429 : 1
99233 : 1

Every number occurs once, making  the maximum number of occurrences for any number in . Because we have multiple values to choose from, we want to select the smallest one, , and print it on a new line.

https://www.hackerrank.com/challenges/s10-basic-statistics/problem

	from collections import Counter
	n = int(input().strip()) # number of elements
	# list comprehension
	# converting from list of str numbers into list of int numbers
	numbers = [int(n) for n in input().split()]
	# average = sum of all numbers / total numbers
	def calculate_mean(numbers):
	s = sum(numbers) # using sum function pythonic way
	N = len(numbers)
	mean = s/N
	return mean
	# median another way to find average
	# sort the numbers and pick center one depends on whether there are even or odd number of elements
	# even elements pick center one and next one . Find average of both
	# odd elements pick center one
	def calculte_median(numbers):
	N = len(numbers)
	numbers.sort() # don't forget to sort
	if N % 2 == 0: # even need two values
	m1 = N/2 # center element float division is used here
	m2 = (N/2) + 1 # next value
	# now i need index of these numbers by subtracting one
	m1 = int(m1) - 1 # converting to int
	m2 = int(m2) - 1
	median = (numbers[m1] + numbers[m2]) / 2 # getting values from index and finding mean
	else: # odd elements
	m = (N+1)/2 # add one to make it even to find center one
	m = int(m1) - 1 # index
	median = numbers[m]
	return median
	def calculate_mode(numbsers):
	# converting to list key=> number : value=> frequency containing tuples
	c = Counter(numbers)
	# applying method on object and getting first tuple first value
	mode = c.most_common()[0][0] # from c object
	return mode
	print(calculate_mean(numbers))
	print(calculte_median(numbers))
	print(calculate_mode(numbers))

view raw Day0Stat.py hosted with ❤ by GitHub