Suppose that the flying hours for aircraft operated by regional airlines in the U. S. during 2006 are normally distributed with mean 2500 and standard deviation 400. Find the number of flying hours such that about 97.5% of the aircraft has flying hours exceeding this number. A) 1,700
B) 2,100
C) 2.500
D) 2,900
E) 3,300

Step-by-step explanation:

Given that :

Mean (μ) = 2500

Standard deviation (σ) = 400

P = 97.5% = 0.975

Zscore corresponding to p(z > x) = 0.975

Z = - 1.96 ( Z probability calculator)

Using the relation :

Zscore = (score (x) - μ) / σ

-1.96 = (x - 2500) / 400

x - 2500 = 400 * - 1.96

x - 2500 = - 784

x = - 784 + 2500

x = 1716

Hence, number of flying hours required is 1716

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.