Given three floating-point numbers x, y, and z we calculate their population standard deviation as follows: first compute the average of the three numbers, then compute the squares of the differences of x, y and z with the average value, and finally calculate the square root of the average of the squared differences. Output the final standard deviation value (for instance, stored in variable, std_deviation) as a floating-point with three digits after the decimal point: print('{:.3f}'.format(std_deviation ))

Write a program that prints the day number of the year, given the date in the form month-day-year. for example, if the input is 1-1-2006, the day number is 1; if the input is 12-25-2006, the day number is 359. the program should check for a leap year. a year is a leap year if it is divisible by 4, but not divisible by 100. for example, 1992 and 2008 are divisible by 4, but not by 100. a year that is divisible by 100 is a leap year if it is also divisible by 400. for example, 1600 and 2000 are divisible by 400. however, 1800 is not a leap year because 1800 is not divisible by 400.