Answer:
Slope = 3
Step-by-step explanation:
2 - 8 = -6
2 - 4 = -2
0.1469
Given from the question;
Mean=8.4 hrs=μ
Standard deviation=1.8 hrs=δ
Sample size, n=40
Let x=8.7
z=(x-μ)÷(δ÷√n)
Find z(8.7)
z=(8.7-8.4)÷(1.8÷√40)
z={0.3×√40}÷1.8=1.05409
z=1.0541
Read from the standard normal probabilities table
P(z>1.0541)
=0.1459
