N-10+9n-3
n+9n=10n
10-3=7
so the answer is....
-13+10n
Answer:
see explanation
Step-by-step explanation:
(
)(t) = 
= 
Answer:
0.1469
Step-by-step explanation:
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
My only issue is that it says numbers between. It does not say including. Therefore, I think you want to use > and < instead of the ones with equals signs attached.
