Page 396 - Basic College Mathematics with Early Integers

S E C T I O N 5.2 I PROPORTIONS 373

a c
71. If the proportion = is a true proportion, write 72. Write a true proportion.
b d
two other true proportions using the same letters.

73. Explain the difference between a ratio and a 74. Explain how to find the unknown number in a
proportion. n 12
proportion such as = .
18 8

For each proportion, find the unknown number n. For Exercises 75 through 80, round your answer to the given place value.

3.2 n 1.8 2.5
75. = 76. =
0.3 1.4 n 8.4
Round to the nearest tenth. Round to the nearest tenth.

n 0.08 4.25 5
77. = 78. =
5.2 6 6.03 n
Round to the nearest hundredth. Round to the nearest hundredth.

43 8 n 18
79. = 80. =
17 n 12 7
Round to the nearest thousandth. Round to the nearest thousandth.

n 0 0 n n 588
81. = 82. = 83. =
7 8 2 3.5 1150 483

585 117 222 37 1425 n
84. = 85. = 86. =
n 474 1515 n 1062 177