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Finding the Fourth Proportional to 721.31, 1,075.14 and 715.64

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Solution

The fourth proportional to 721.31, 1,075.14 and 715.64 is: 1,066.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.31 : 1,075.14 = 715.64 : x
  2. Step 2: Convert to fraction form
    721.31/1,075.14 = 715.64/x
  3. Step 3: Cross multiply
    721.31x = 1,075.14 × 715.64
  4. Step 4: Simplify right side
    721.31x = 769,407.81
  5. Step 5: Solve for x
    x = 769,407.81/721.31
  6. Step 6: Final answer
    x = 1,066.69

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.