Solution:
Rewrite 3 ≥ y - 2 for easier calculation:
y - 2 ≤ 3
Move the term:
y ≤ 3 + 2
y ≤ 5
When graphing the solution, filled dot (black arrow) is used for ≤ and ≥ while empty dot (white arrow) is used for < >
Answer:
option (D) 16.5
Step-by-step explanation:
Data provided:
Sleep time of , X = 15.9 is at the 10th percentile
Standard deviation, σ = 0.5 hour
also,
10th percentile of normal distribution is
Z = F⁻¹(0.10)
or
Z = - 1.28 (Using Standard Normal distribution)
Now,

or
X = μ + ( σ × Z )
or
μ = X - ( σ × Z )
on substituting the respective values, we get
μ = 15.9 - 0.5 × (-1.28)
or
μ = 16.5
Hence, the correct answer is option (D) 16.5