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Finding the Fourth Proportional to 458.76, 688.74 and 390.72

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Solution

The fourth proportional to 458.76, 688.74 and 390.72 is: 586.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.76 : 688.74 = 390.72 : x
  2. Step 2: Convert to fraction form
    458.76/688.74 = 390.72/x
  3. Step 3: Cross multiply
    458.76x = 688.74 × 390.72
  4. Step 4: Simplify right side
    458.76x = 269,104.49
  5. Step 5: Solve for x
    x = 269,104.49/458.76
  6. Step 6: Final answer
    x = 586.59

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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.