Unlike total range, the interquartile range has a breakdown point of 50%, and is thus often preferred to the total range. The IQR is used to build box plots, simple graphical representations of a probability distribution.igure 3. Box-and-whisker plot with four close and one far away extreme values, defined as outliers above Q3 + 1.5(IQR) and Q3 + 3(IQR), respectively. The interquartile range is often used to find outliers in data. Outliers are observations that fall below Q1 - 1.5(IQR) or above Q3 + 1.5(IQR).
Medical Definition of Heart murmur. Heart murmur: An unusual, 'whooshing' heart sound that may be innocent or may reflect disease or malformation. A heart murmur is created by blood flow through a heart valve, by blood flow through a narrowed chamber, or by an unusual connection between the chambers, as seen with congenital heart disease.
Still's murmur a functional heart murmur of childhood, with a buzzing or vibratory tone heard in midsystole; it usually disappears by puberty. systolic murmur a heart murmur heard at systole, usually due to mitral or tricuspid regurgitation or to aortic or pulmonary obstruction.