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Finding the Fourth Proportional to 499.21, 688.90 and 278.15

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Solution

The fourth proportional to 499.21, 688.90 and 278.15 is: 383.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.21 : 688.90 = 278.15 : x
  2. Step 2: Convert to fraction form
    499.21/688.90 = 278.15/x
  3. Step 3: Cross multiply
    499.21x = 688.90 × 278.15
  4. Step 4: Simplify right side
    499.21x = 191,617.54
  5. Step 5: Solve for x
    x = 191,617.54/499.21
  6. Step 6: Final answer
    x = 383.84

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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.