hello : <span>(-101)+102+(-103)+104+...+(-199)+200 =( </span>(-101)+(-103) +....+ (-199) ) +( (102) + ( 104) +....+(200)) let : A = ( (-101)+(-103) +....+ (-199) ) B = ( (102) + ( 104) +....+(200)) note : the sum n term of arithemtic sequence S= n/2(u1 + un) un = u1 +(n-1) d u1 : the first term d : the common diference in A : u1= -101 d = -2 n = 49... in B : u1 =102 d=2 n= 49 A = 49/2(-101-199) =-7350 B=49/2(102+200)=4949 (-101)+102+(-103)+104+...+(-199)+200 = A+B =-2401
only the first statement is true - it is the experimental probability. the rest is incorrect: the ratio is not the number of trials; the theoretical probability should be 0.5 (for unbiased coins); ratio never represents a number of occurences.
