Problem: Shekhar Dhanraj, brand manager of Midnight Melodies Band is contemplating a research among their audience for live concerts. He knew that 30% of their audiences were women, spanning all market categories. Shekhar recalled a huge fanfare for live concerts in their markets, from among youngsters (below 30 years), as reported in Music Today, an authentic report on music bands in the country. This report found that 70% of concerts were attended by people below 30 years. Shekhar wanted to get information from all the relevant consumer groups. Help Shekhar in deciding a suitable sampling approach. Justify your recommendation.