probabilty

Question

Let X be the score when a cube with faces 1 through 6 is rolled. You are given  that E(X)= 3.5 and SD(X) =1.708.

A cube with faces 1 thru 6 is rolled 50 times. Which of the following most closely approximates the probability that the total score is atleast 200.

 

a)0.000

b)0.019

c)0.385

d)0.483

e)0.5

Answer 1

mean =175

z = (200-175)/1.708/sqr50 >245/1.700= about 103.5

probability of 200 or more is virtually zero