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Finding the Fourth Proportional to 687.71, 1,031.67 and 445.32

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Solution

The fourth proportional to 687.71, 1,031.67 and 445.32 is: 668.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.71 : 1,031.67 = 445.32 : x
  2. Step 2: Convert to fraction form
    687.71/1,031.67 = 445.32/x
  3. Step 3: Cross multiply
    687.71x = 1,031.67 × 445.32
  4. Step 4: Simplify right side
    687.71x = 459,423.28
  5. Step 5: Solve for x
    x = 459,423.28/687.71
  6. Step 6: Final answer
    x = 668.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.