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Finding the Fourth Proportional to 499.10, 688.78 and 278.05

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Solution

The fourth proportional to 499.10, 688.78 and 278.05 is: 383.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.10 : 688.78 = 278.05 : x
  2. Step 2: Convert to fraction form
    499.10/688.78 = 278.05/x
  3. Step 3: Cross multiply
    499.10x = 688.78 × 278.05
  4. Step 4: Simplify right side
    499.10x = 191,512.86
  5. Step 5: Solve for x
    x = 191,512.86/499.10
  6. Step 6: Final answer
    x = 383.71

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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.