300 miles divided by 6 hours is a rate question. So the answer would be 50 miles per hour
Answer:
0.8041
Step-by-step explanation:
We know that
μ=72 and σ=5
and P(65<X<78)
We can determine the Z value as (X-μ)/σ
P( 65<X<78 )=P( 65-72< X-μ<78-72)


To fine the Z values:

From the standard normal tables:

to find P ( Z<-1.4)

From the standard normal tables:

Therefore


Answer: The plane was flying at 40.3636 mph
Step-by-step explanation: Simply divide the total miles by how fast the plane was going.
The answer is: (z - 6)(z + 15)
z² + 9z - 90 = z*z + 15z - 6z - 6*15 =
= (z*z + 15z) - (6z + 6*15) =
= z(z + 15) - 6(z + 15) =
= (z - 6)(z + 15)