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Finding the Fourth Proportional to 521.91, 720.54 and 389.86

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Solution

The fourth proportional to 521.91, 720.54 and 389.86 is: 538.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.91 : 720.54 = 389.86 : x
  2. Step 2: Convert to fraction form
    521.91/720.54 = 389.86/x
  3. Step 3: Cross multiply
    521.91x = 720.54 × 389.86
  4. Step 4: Simplify right side
    521.91x = 280,909.72
  5. Step 5: Solve for x
    x = 280,909.72/521.91
  6. Step 6: Final answer
    x = 538.23

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.