An analogous formula applies to the case of a continuous probability distribution. Not every probability distribution has a defined mean; see the Cauchy distribution for an example. Moreover, for some distributions the mean is infinite: for example, when the probability of the value is for n = 1, 2, 3, ....
Red blood cell (RBC) production (erythropoiesis) takes place in the bone marrow under the control of the hormone erythropoietin (EPO). Juxtaglomerular cells in the kidney produce EPO in response to decreased O 2 delivery (as in anemia and hypoxia) and increased levels of androgens.
1 Red blood cell production increases to compensate for lower oxygen levels at higher altitudes. 2  The kidneys release too much of a protein (erythropoietin, or EPO) that enhances red blood cell production. 3  The bone marrow is producing too many red blood cells.4  The oxygen-carrying capacity of red blood cells is reduced. Red blood cell production increases to compensate for lower oxygen levels at higher altitudes. 2  The kidneys release too much of a protein (erythropoietin, or EPO) that enhances red blood cell production. 3  The bone marrow is producing too many red blood cells. 4  The oxygen-carrying capacity of red blood cells is reduced.