17. Airlines must be aware of the weight of the aircraft plus everything on board. Based on thousands of flights, the mean and standard deviation for the weights of several items are shown in
the table. The weights of the airplane, people/luggage, and fuel are assumed to be independent.
Item
Mean (in
tons)
Plane
45
People/luggage 10
Fuel
20
Standard Deviation (in
tons)
2
1
1
Let the random variable T represent the total weight of the plane, people/luggage, and fuel for a
randomly selected flight. Which of the following is closest to the standard deviation of T?
04.00 tons
120 tons
2.45 tons
O 6.00 tons
0 75.0 tons

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,

whole numbers.

step-by-step explanation:

we are given the average monthly rainfall (in millimeters) model r(m) for the years 1900-2009 as a function of the month number m.

as we can see m is taken for the number of months for years 1900-2009.

we know that number of months can't be a negative number or decimal number or a fraction.

so, the number of months could be only positive whole numbers.

therefore, whole numbers is more appropriate for the domain of r.