# Program to calculate the average and std dev
# using a function call. Returns two values.

# our function 'avg' is defined here
def avg(nums):
    sum = 0.0
    sum1 = 0.0
    for i in range(len(nums)):
       sum = sum + nums[i]
       sum1 = sum1 + nums[i]**2
    average = sum/len(nums)
    sd = sqrt( sum1/len(nums) )
    return average, sd

# Main program begins here.

nums = [8.2, 4.5, 7.3, 7, 56.0, 7.9, 100.4]
mean, sd = avg( nums )

print("The mean is : ", mean)
print("The standard deviation is : ", sd)