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Finding the Fourth Proportional to 455.19, 628.61 and 389.31

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Solution

The fourth proportional to 455.19, 628.61 and 389.31 is: 537.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.19 : 628.61 = 389.31 : x
  2. Step 2: Convert to fraction form
    455.19/628.61 = 389.31/x
  3. Step 3: Cross multiply
    455.19x = 628.61 × 389.31
  4. Step 4: Simplify right side
    455.19x = 244,722.21
  5. Step 5: Solve for x
    x = 244,722.21/455.19
  6. Step 6: Final answer
    x = 537.63

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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.