The first quartile (Q 1) is defined as the middle number between the smallest number and the median of the data set.The second quartile (Q 2) is the median of the data. Use the median to divide the ordered data set into two halves. 2  If the median is a datum (as opposed to being the mean of the middle two data), include the median in both halves. 3  The lower quartile value is the median of the lower half of the data.
Many people associate shaky hands with Parkinsonâs disease, but the most common cause of shaking hands is actually essential tremor. Essential tremor is the most common neurologic disorder affecting adults, but itâs not well understood.
Unsteadiness Unsteadiness (disequilibrium) or loss of balance when standing or walking are often experienced along with vertigo and other types of dizziness. The causes include: 1  Inner ear problems. 2  These can cause sensations of floating or unsteadiness, especially in the dark. 3  Vision problems. 4  Cataracts, macular degeneration, glaucoma and weakening eyesight (reduced visual acuity) are risk factors for disequilibrium. 5  Numbness.