Probability: Given the Mean and Standard deviation

[Nikki10]

Homework Statement

The distribution of a drugs among addicts with autoimmune disorder is N(6.9, 16.81). What is the probability that one of these addicts enters your office and reports taking 16 drugs or more?

The Attempt at a Solution

z = (16-6.9)/4.1 = 2.21
P(z >16) = 0.014 from the table
so P(z > 16) = 0.014 or 1.4%

Is this correct. It seems to simple and maybe I don't understand the concept

 

[issacnewton]

your answer is correct but you should have written
$$P[x\geq 16]=1-P[x < 16]$$

$$P[x\geq 16]=1-P[z < 2.21]= 1-0.986$$

so your answer is correct...

 

[Nikki10]

thank you