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Question : Suppose that z varies jointly with x and y and that z : 2163519

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Determine whether the expression is rational.

221) The fixed monthly payment required to amortize a loan of L dollars over a term of n months at an annual interest rate of r is given by ((Lr/12)/1 - (1 + (r/12))^{-n}). Evaluate this expression when L = $200,000, r = 0.07, and n = 360 months .

A) $1264.07

B) $1463.67

C) $1397.14

D) $1330.60

Solve the proportion.

222) (1/3) = (x/18)

A) 18

B) 6

C) 3

D) 15

223) (3/5) = (x/15)

A) 11

B) 9

C) 6

D) 15

224) (6/8) = (x/24)

A) 48

B) 6

C) 18

D) 144

225) (14/x) = (9/18)

A) 28

B) 252

C) 14

D) 126

226) (9/x) = (23/138)

A) 15

B) 54

C) 9

D) 106

Write a proportion that models the situation described. Then, solve the proportion for x.

227) 11 is to 12, as 3 is to x

A) (11/12) = (3/x); x = (38/11)

B) (11/12) = (3/x); x = (36/11)

C) (11/12) = (x/3); x = (33/10)

D) (11/12) = (x/3); x = (11/4)

228) A rectangle has sides of 6 and 11. In a similar rectangle, the longer side is 44 and the shorter side is x.

A) (6/11) = (x/44); x = 26

B) (6/11) = (x/44); x = 24

C) (6/11) = (44/x); x = (242/3)

D) (6/11) = (44/x); x = (487/6)

229) If 3.3 ounces of oil are to be added to 16.5 gallons of gasoline, then x ounces of oil should be added to 39.5 gallons of gasoline.

A) (3.3/16.5) = (x/39.5); x = 7.9 ounces

B) (3.3/16.5) = (x/39.5); x = 8.1 ounces

C) (3.3/16.5) = (x/39.5); x = 7.8 ounces

D) (16.5/3.3) = (x/39.5); x = 197.5 ounces

230) If at a given speed a car can travel 142.8 miles on 6 gallons of gasoline, then the car can travel x miles on 102 gallons of gasoline at that speed.

A) (142.8/6) = (x/102); x = 2435 miles

B) (6/142.8) = (x/102); x = 2427.6 miles

C) (142.8/6) = (x/102); x = 2427.6 miles

D) (6/142.8) = (x/102); x = 2435 miles

Solve the problem.

231) Suppose that y is directly proportional to x and that y = 40 when x = 8. Find the constant of proportionality k. Then use y = kx to find y when x = 17.

A) k = 5; y = 85

B) k = - 5; y = - 85

C) k = 7; y = 119

D) k = 320; y = (320/17)

232) Suppose that y is directly proportional to x and that y = 39 when x = 6. Find the constant of proportionality k. Then use y = kx to find y when x = 15.

A) k = 6.5; y = 112.5

B) k = 234; y = (78/5)

C) k = 6.5; y = 97.5

D) k = 6.25; y = 93.75

233) Suppose that y is directly proportional to x and that y = 14.4 when x = 6. Find the constant of proportionality k. Then use y = kx to find y when x = 15.

A) k = 2.6; y = 36

B) k = 86.4; y = (86.4/15)

C) k = 2.4; y = 39

D) k = 2.4; y = 36

234) Suppose that y is directly proportional to x and that y = 3.5 when x = 7. Find the constant of proportionality k. Then use y = kx to find y when x = 10.

A) k = 1.5; y = 4

B) k = 24.5; y = (49/20)

C) k = 0.5; y = 5

D) k = 0.5; y = 4

235) Suppose that y is inversely proportional to x and that y = 40 when x = 9. Find the constant of proportionality k. Then use y = (k/x) to find y when x = 8.

A) k = (40/9); y = (320/9)

B) k = 180; y = 22.5

C) k = 360; y = 45

D) k = 72; y = 9

236) Suppose that y is inversely proportional to x and that y = 17.5 when x = 5. Find the constant of proportionality k. Then use y = (k/x) to find y when x = 25.

A) k = 3.5; y = 87.5

B) k = 80; y = 3.2

C) k = 87.5; y = 3.5

D) k = 95; y = 3.8

237) Suppose that y is inversely proportional to x and that y = 26.4 when x = 6. Find the constant of proportionality k. Then use y = (k/x) to find y when x = 36.

A) k = 176.4; y = 4.9

B) k = 4.4; y = 158.4

C) k = 158.4; y = 4.4

D) k = 146.4; y = 4.4

238) Suppose that y is inversely proportional to x and that y = 3.5 when x = 7. Find the constant of proportionality k. Then use y = (k/x) to find y when x = 10.

A) k = 9.8; y = (49/50)

B) k = 24.5; y = (49/20)

C) k = 4.9; y = (49/20)

D) k = 0.5; y = 5

Solve the problem. Round amounts to the nearest tenth if necessary.

239) Suppose that z varies jointly with x and y and that z = 405 when x = 9 and y = 15. Find the constant of variation k. Then use z = kxy to find z when x = 3 and y = 4.

A) k = 5; z = 60

B) k = 54,675; z = (18225/4)

C) k = 0.3; z = 3.6

D) k = 3; z = 36

240) Suppose that z varies jointly with x and y and that z = 1080 when x = 9 and y = 16. Find the constant of variation k. Then use z = kxy to find z when x = 3 and y = 10.

A) k = 7.8; z = 234

B) k = 7.5; z = 225

C) k = 155,520; z = 5184

D) k = 7.3; z = 219