Answer:
The folllowing are the code to this question:
Sum= 0.0#defining float variable Sum
n = 0# defining integer variable n for count number
while True:#defining for loop for calculate Sum
number= input("Enter a number and for exit press Enter: ")#defining number variable for user input
if number== '':#defining if block that checks number is empty
break#use break key word
ad= float(number)#convert the string value into float
Sum += ad #add value in sum variable
n += 1#increment the value of n
print("The sum is: ", Sum)
if n > 0:#use if for calculate average
avg = Sum / n #calculate average value
print('The average is', avg)#use print method to print average value
else:#else block
print('undefined')#print message undefined
Output:
please find the attached file.
Step-by-step explanation:
In the above code, the "Sum and n" variable is defined, which is used for calculating the sum and in the next step, a while loop is used in the loop number variable is defined, that input value from the user end and if the block is used, that check last value.
In the loop, the "Sum" variable is used, which adds user input value, and n is used for times of inputs, and outside the loop, the conditional statement is used.
In the if block, it checks count value is greater then 0, if it is true, it will calculate the average and store its value in the "avg" variable, otherwise, it will print 'undefined' as a message.