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Finding the Fourth Proportional to 499.99, 689.80 and 278.89

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Solution

The fourth proportional to 499.99, 689.80 and 278.89 is: 384.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.99 : 689.80 = 278.89 : x
  2. Step 2: Convert to fraction form
    499.99/689.80 = 278.89/x
  3. Step 3: Cross multiply
    499.99x = 689.80 × 278.89
  4. Step 4: Simplify right side
    499.99x = 192,378.32
  5. Step 5: Solve for x
    x = 192,378.32/499.99
  6. Step 6: Final answer
    x = 384.76

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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.