22. Name the function to create histogram from DataFrame. 23. Name some functions used to join or combine dataframes. 24. Name two functions that can produce result similar to SQL joins.

Ans:
22. We can use plot() function of dataframe to create histogram.
Syntax:
<dataframe>.plot(kind = ‘hist’)
23. concat(), join() and merge() can be used to combine multiple dataframes.
24. merge() and join()