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Finding the Fourth Proportional to 289.80, 399.84 and 207.12

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Solution

The fourth proportional to 289.80, 399.84 and 207.12 is: 285.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.80 : 399.84 = 207.12 : x
  2. Step 2: Convert to fraction form
    289.80/399.84 = 207.12/x
  3. Step 3: Cross multiply
    289.80x = 399.84 × 207.12
  4. Step 4: Simplify right side
    289.80x = 82,814.86
  5. Step 5: Solve for x
    x = 82,814.86/289.80
  6. Step 6: Final answer
    x = 285.77

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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.