import csv
with open('HW.csv',newline='') as f:
    reader=csv.reader(f)
    file_data=list(reader)

file_data.pop(0) 
#sorting the data to get height
new_data=[]
for i in range(len(file_data)):
    n_num=file_data[i][2]
    new_data.append(float(n_num))

#getting the mean
n=len(new_data)
total=0
for x in new_data:
    total +=x

mean=total/n
print('Mean/average is: '+str(mean))