System Management Overview

Solution 1Q

a) Random sample of n is given as 10 Australian workers selected

Probability that more than seven of them say job stress

Given:

n =10

Probability p (x) = 70% = 0.7

More than seven say job stress caused frequent health problems p (x ˃7) = Ɂ

P (x ˃7) = p (x = 8) + p (x = 9) + p (x = 10)

Binomial distribution:

P (x ˃7) = p (x = 8) + p (x = 9) + p (x = 10) =

10! / 8! (10-8)! *0.78 (1- 0.7)10-8 + 10! / 9! (10-9)* 0.79 (1 - 0.7) 10-9 +

10!/10!(10-10)!*0.710(1-0.7)10-10

Using binomial tables find n and p, and the relevant probabilities are:

P (x ˃ 7) = p (x = 8) + p (x =9) + p (x = 10)

= 0.233 + 0.121 + 0.028

= 0.382

The probability that more than seven of them say job stress caused frequent health

Problems.

b) The expected value is given 0.7

Random Sample is given as 10

The mean, or expected value, of the binomial distribution formula is:

Mean:

Whereas n = 10

P = 0.7

= 10 *(0.7)

= 7

So