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Finding the Fourth Proportional to 651.76, 899.43 and 389.78

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Solution

The fourth proportional to 651.76, 899.43 and 389.78 is: 537.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    651.76 : 899.43 = 389.78 : x
  2. Step 2: Convert to fraction form
    651.76/899.43 = 389.78/x
  3. Step 3: Cross multiply
    651.76x = 899.43 × 389.78
  4. Step 4: Simplify right side
    651.76x = 350,579.83
  5. Step 5: Solve for x
    x = 350,579.83/651.76
  6. Step 6: Final answer
    x = 537.90

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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.