Answer:
68%
Step-by-step explanation:
Given :
Mean, μ = 21
Standard deviation, σ = 15
Recall :
Zscore = (x - μ) / σ
P(Z =(x - μ) / σ) - P(Z =(x - μ) / σ)
x = 6 and x = 36
P(Z =(36 - 21) / 15) - P(Z =(6 - 21) / 15)
P(Z = 1) - P(Z = - 1)
Using the Z probability calculator :
P(Z = - 1) = 0.15866
P(Z = 1) = 0.84134
0.84134 - 0.15866
= 0.68268
= 0.68
= 68%