1 The level of significant difference you are hoping to show (e.g. p p value takes more study power. 2  The frequency of the outcome in the two groups. 3  Imagine an exposure that increases incidence by a third: it is easier to show a difference between 30 and 45 percent than between 10 and 15 per cent.
Name of Instrument: Bass drum. Family: Percussion. How to Play: The bass drum is played by using padded beaters or sticks and striking it against the drumhead. In a drum set, the musician plays the bass drum by using a pedal-operated stick. Types: The bass drums that are used in marching bands and military music have two drumheads.
gong, tam-tam - a percussion instrument consisting of a metal plate that is struck with a softheaded drumstick. kettledrum, timpani, tympani, tympanum, kettle - a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it.