Math Glossary Letter H half-dollar noun Currency unit worth 50 cents half-life noun time required for a quantity to reduce to half its initial value hardy-weinberg noun allele and genotype frequencies in a population will remain constant from generation to generation harmonic mean noun reciprocal of the arithmetic mean of the reciprocals of the given set of observations harmonic sequence noun sequence of real numbers formed by taking the reciprocals of an arithmetic progressio HDL noun High Density Lipoproteins - a good cholesterol health noun functional and metabolic efficiency of humans heart noun Organ which pumps blood heat noun energy that is transferred from one body to another as the result of a difference in temperature heat index noun measure of how hot it really feels when relative humidity is factored in with the actual air temperature hectare noun unit of area equal to 100 ares height noun the distance from the bottom to the top of something standing upright hemisphere noun half of a sphere heptagon noun seven sided figure Herfindahl Index noun accepted measure of market concentration. Herons Formula noun formula to find the area of a triangle using the 3 side lengthsS = (A + B + C)/2; A = sqrt(S(S - A)(S - B)(S - C)) hertz noun unit of frequency in the International System of Units (SI) and is defined as one cycle per second hexadecimal noun Base 16 number system hexagon noun six sided figure high and low method noun taking the highest level of activity and the lowest level of activity and comparing the total costs at each level highly suspect outliers noun Values below 3 * Interquartile Range below the lower quartile or Values above 3 * Interquartile Range above the upper quartile hinge noun object used to mount and operate doors horizontal component noun x portion of a vector hour noun Unit of time equal to 60 minutes hue noun color shade hyperbola noun conic section defined as the locus of all points in the plane the difference of whose distances and from two fixed points hyperbolic inverse noun multivalued function that are the inverse functions of the hyperbolic functions hypergeometric distribution noun discrete probability distribution that describes the probability of k successes (random draws for which the object drawn has a specified feature) in ndraws, without replacement hypotenuse noun the longest side of a right triangle, opposite the right angle. hypothesis noun statistical test using a statement of a possible explanation for some conclusions hypothesis testing verb statistical test using a statement of a possible explanation for some conclusions hypothesis testing for a proportion noun an act in statistics whereby an analyst tests an assumption regarding a population proportion hypothesis testing for the mean noun an act in statistics whereby an analyst tests an assumption regarding a population mean