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Finding the Fourth Proportional to 499.90, 689.85 and 278.86

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Solution

The fourth proportional to 499.90, 689.85 and 278.86 is: 384.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.90 : 689.85 = 278.86 : x
  2. Step 2: Convert to fraction form
    499.90/689.85 = 278.86/x
  3. Step 3: Cross multiply
    499.90x = 689.85 × 278.86
  4. Step 4: Simplify right side
    499.90x = 192,371.57
  5. Step 5: Solve for x
    x = 192,371.57/499.90
  6. Step 6: Final answer
    x = 384.82

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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.