The probability model below describes the number of calls, the repair of a device at a workshop may call Stunde.Repair 0 1 2 3 0th 0th 0th 3Wahrscheinlichkeit a 4 0th 2a) How many calls the store should expect now? Explain your answer. . B) What is the standard deviation?
Tags: Appliance, below, calls, describes, model, number, probability, receive, Repair, shop
The expected number of calls per hour is the mean value. It is obtained as ’sum of xp’. Here it is 0*0.1+1*0.3+2*0.4+3*0.2 = 1.7 (the symbol * indicates multiplication). Thus an average of 1.7 calls may be expected during one hour.
The standard deviation will be E(x^2) – (E(x))^2. This can be calculated as 0^2*0.1 +1^2*0.3+2^2*0.4+3^2*0.2 – 1.7^2 = 0+0.3+4*0.4+9*0.2 – 1.7^2 =3.7 – 2,89 =0.81.