Texas Instruments TI-89 User Manual - Page 893

variance( ) MATH/Statistics menu variance(list[, freqlist]) ⇒ expression Returns the variance of list. Each freqlist element counts the number of consecutive occurrences of the corresponding element in list. Note: list must contain at least two elements. variance(matrix1[, freqmatrix]) ⇒ matrix Returns a row vector containing the variance of each column in matrix1. Each freqmatrix element counts the number of consecutive occurrences of the corresponding element in matrix1. Note: matrix1 must contain at least two rows. when() CATALOG when(condition, trueResult [, falseResult] [, unknownResult]) ⇒ expression Returns trueResult, falseResult, or unknownResult, depending on whether condition is true, false, or unknown. Returns the input if there are too few arguments to specify the appropriate result. Omit both falseResult and unknownResult to make an expression defined only in the region where condition is true. Use an undef falseResult to define an expression that graphs only on an interval. variance({a,b,c}) ¸ añ -aø (b+c)+bñ -bø c+cñ 3 variance({1,2,5,ë 6,3,ë 2}) ¸ 31/2 variance({1,3,5},{4,6,2}) ¸ 68/33 variance([1,2,5;ë 3,0,1; .5,.7,3]) ¸ [4.75 1.03 4] variance([L1.1,2.2;3.4,5.1; L2.3,4.3],[6,3;2,4;5,1]) ¸ [3.91731,2.08411] when(x