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Finding the Fourth Proportional to 399.85, 551.14 and 312.37

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Solution

The fourth proportional to 399.85, 551.14 and 312.37 is: 430.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.85 : 551.14 = 312.37 : x
  2. Step 2: Convert to fraction form
    399.85/551.14 = 312.37/x
  3. Step 3: Cross multiply
    399.85x = 551.14 × 312.37
  4. Step 4: Simplify right side
    399.85x = 172,159.60
  5. Step 5: Solve for x
    x = 172,159.60/399.85
  6. Step 6: Final answer
    x = 430.56

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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.