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Finding the Fourth Proportional to 515.61, 771.80 and 485.64

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Solution

The fourth proportional to 515.61, 771.80 and 485.64 is: 726.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.61 : 771.80 = 485.64 : x
  2. Step 2: Convert to fraction form
    515.61/771.80 = 485.64/x
  3. Step 3: Cross multiply
    515.61x = 771.80 × 485.64
  4. Step 4: Simplify right side
    515.61x = 374,814.52
  5. Step 5: Solve for x
    x = 374,814.52/515.61
  6. Step 6: Final answer
    x = 726.93

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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.