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Finding the Fourth Proportional to 522.40, 721 and 397.86

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Solution

The fourth proportional to 522.40, 721 and 397.86 is: 549.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.40 : 721 = 397.86 : x
  2. Step 2: Convert to fraction form
    522.40/721 = 397.86/x
  3. Step 3: Cross multiply
    522.40x = 721 × 397.86
  4. Step 4: Simplify right side
    522.40x = 286,857.06
  5. Step 5: Solve for x
    x = 286,857.06/522.40
  6. Step 6: Final answer
    x = 549.11

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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.