A soap manufacturer wanted to know what percentage of the citizens of X city use his soap. He conducted a survey and found that out of 500 persons (selected at random) only 10% use his soap. He spent Tk.500000 on an advertisement campaign to attract more customers. In order to know the results of the campaign he conducted another survey and found that out of 600 persons 15% are using his soap. Do you think that the advertisement campaign has really increased the percentage of citizens of X city using his soap?