Answer
Given p = 31% = 0.31 and n = 6
a. Mean = n x p
= 6 x 0.31 = 1.86
b. Variance = n x p (1-p)
= 6 x 0.31 (0.69) = 1.3
c. S.D = \sqrt Variance
=\sqrt 1.28 = 1.1
d. On average 1.86 out of 6 adults think that life existed on Mars at some point in time. samples would differ from mean by at most 1.1 (Standard deviation)
Work Step by Step
As given in answer