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.
Drums are the world's oldest and most ubiquitous musical instruments, and the basic design has remained virtually unchanged for thousands of years. Drums may be played individually, with the player using a single drum, and some drums such as the djembe are almost always played in this way. Others are normally played in a set of two or more, all played by the one player, such as bongo drums and timpani.