Practice PHW14: Final Exam Review

stat.py

Create a program stat.py that finds the mean, median, and mode in a list of numbers read in from a file numbers.txt. Do not use the python statistics package. Some definitions:

• mean: the sum of the numbers divided by the number of numbers.
• median: the middle number in a sorted list of numbers. If there is an even number of numbers, the median is the average of the middle two numbers.
• mode: the most frequently occurring number.

Recommended Development Steps:

1. Instead of reading in from a file, create a list of numbers with list(range(1,11)) and then append(1) to your list so you will have a mode. Print out the numbers.
2. Print out the mean for the list of numbers.
3. Print out the median for the list of numbers.
4. Print out the mode for the list of numbers.
5. Append another 1 to your list and print out the mean, median, and mode.
6. Read in a file numbers.txt, which should have a number entered one per line.
7. Write functions to read in the data from a file & calculate each statistic:
   • file_input(filename): returns the list of numbers read in from file filename
   • mean(numbers): takes a list of numbers as a parameter and returns their mean
   • median(numbers): takes a list of numbers as a parameter and returns their median
   • mode(numbers): takes a list of numbers as a parameter and returns their mode

Hints:

• There are two different ways to sort a list: sorted and sort. The function sorted(list) returns a sorted version of the list without modifying the original, whereas list.sort() doesn’t return anything but does change the original:

  >>> list = [5, 7, 5, 1, 5]
  >>> sorted(list)
  [1, 5, 5, 5, 7]
  >>> print(list)
  [5, 7, 5, 1, 5]
  >>> list.sort()
  >>> print(list)
  [1, 5, 5, 5, 7]
  

• Make sure you don’t have any blank lines in your file.

Solution

When you’ve attempted the PHW, you can see my solution.