Biology Forums - Study Force

Every year favorite songs compete to be on a Top 200 list based upon sales and rankings by the experts in the music industry. These songs have many characteristics, such as song length and beats per minute, which vary from category to category in the music industry. A disc jockey wondered if the number of beats per minute in songs classified as dance music were lower than the beats per minute in the songs that are ranked on a Top 200 list from 2001. A random sample of songs from each group was selected and the beats per minute are listed in the chart at the right. Does this sample indicate that songs classified as dance music have lower beats per minute than the songs ranked on a Top 200 list?




Test an appropriate hypothesis and state your conclusion.

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Every year favorite songs compete to be on a Top 200 list based upon sales and rankings by the experts in the music industry. These songs have many characteristics, such as song length and beats per minute, which vary from category to category in the music industry. A disc jockey wondered if the number of beats per minute in songs classified as dance music were lower than the beats per minute in the songs that are ranked on a Top 200 list from 2001. A random sample of songs from each group was selected and the beats per minute are listed in the chart at the right. Does this sample indicate that songs classified as dance music have lower beats per minute than the songs ranked on a Top 200 list?




Create and interpret a 90% confidence interval.

We wish to create an interval that is likely to contain the true difference between the mean beats per minute of dance songs and the mean beats per minute of Top 200 songs.

Under these conditions, the sampling model of the difference in the sample means can be modeled by a Student's t-model with about 30 degrees of freedom (from calculator).
We will use a two-sample t-interval.
The 90% confidence interval is: (-0.15, 1.91).
We are 90% confident that dance songs average between 0.15 fewer beats per minute and 1.91 more beats per minute than the Top 200 songs.