17. farimah and helio are standing 15 ft. apart from each other and looking up at a kite that is with the flying between them. farimah is flying the kite on a 57 ft. string at an angle of 68 ground. how far is helio from the kite? 64.1 ft. 56.2 ft 60.0 ft. 53.2 ft.

Helio is 53.2 feet from the kite ⇒ the last answer

Step-by-step explanation:

* Lets change this story problem to a trigonometry problem

- Assume that there is a triangle joining between the

 kite, Farimah and Helio

- The name of the triangle is KFH, where K position of the kite,

 F position of Farimah and H is the position of Helio

∵ Farimah and Helio are standing 15 feet apart from each other

∴ FH = 15 feet

∵ Farimah is flying the kite on a 57 feet string at an angle

 of 68 with the ground

∴ FK = 57 feet

∴ m∠KFH = 68°

∵ We need to know that Helio is how far from the kite

∴ We need to calculate the length of KH

* Now lets find the best way to find the length of KH

 using the trigonometry

- We have the length of two sides and the measure of the included

 angle between them , then the best way is the cosine Rule

* Lets explain the cosine rule:

- In ΔABC:

∵ a is the length of the side opposite to ∠A ⇒ a is BC

∵ b is the length of the side opposite to ∠B ⇒ b is AC

∵ c is the length of the side opposite to ∠C ⇒ c = AB

∴ a² = b² + c² -2bc × cos(A)

∴ b² = a² + c² -2ac × cos(B)

∴ c² = a² + b² -2ab × cos(C)

* We will use the rule in our problem to find HK

∵ FH is k , HK is f , KF is h

∴ f² = h² + k² - 2hk × cos(F)

∵ h = 57 feet , k = 15 feet , m∠F = 68°

∴ f² = (57)² + (15)² - 2(57)(15) × cos(68) = 2833.4227

∴ f = √2833.4227 = 53.2 feet

* Helio is 53.2 feet from the kite

an advantage of the standard deviation is that it increases as the dispersion of the data increases. e. the interquartile range is preferred when the data are not skewed or no have outliers. an advantage of the standard deviation is that it uses all the observations in its computation.