Out of above plotted histograms, which ones can be used for creating frequency polygons?

Q. Out of above plotted histograms, which ones can be used for creating frequency polygons? Can you draw frequency polygons from all the above histograms ?

Answer :-

We can use  step type of histogram to make frequency polygons.

By following script :-

import matplotlib.pyplot as plt

x=[78 ,72, 69 ,81 ,63 ,67 ,65 ,75 ,79 ,74 ,71, 83 ,71 ,79 ,80 ,69 ]
a,bins,c=plt.hist(x,bins=7,histtype='step')
l=list(bins)
l.insert(0,0)
l.insert(len(bins)+1,bins[len(bins)-1])
mid=[]
for i in range(len(l)-1):
      ele=(l[i]+l[i+1])/2
      mid.append(ele)
x=list(a)
x.insert(0,0)
x.insert(len(a)+1,0)
plt.plot(mid,x,'go--')
plt.xlabel("Age")
plt.show()

Output :-