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Finding the Fourth Proportional to 399.90, 599.85 and 255.90

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Solution

The fourth proportional to 399.90, 599.85 and 255.90 is: 383.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.90 : 599.85 = 255.90 : x
  2. Step 2: Convert to fraction form
    399.90/599.85 = 255.90/x
  3. Step 3: Cross multiply
    399.90x = 599.85 × 255.90
  4. Step 4: Simplify right side
    399.90x = 153,501.62
  5. Step 5: Solve for x
    x = 153,501.62/399.90
  6. Step 6: Final answer
    x = 383.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.