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Finding the Fourth Proportional to 515.42, 771.44 and 280.80

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Solution

The fourth proportional to 515.42, 771.44 and 280.80 is: 420.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.42 : 771.44 = 280.80 : x
  2. Step 2: Convert to fraction form
    515.42/771.44 = 280.80/x
  3. Step 3: Cross multiply
    515.42x = 771.44 × 280.80
  4. Step 4: Simplify right side
    515.42x = 216,618.95
  5. Step 5: Solve for x
    x = 216,618.95/515.42
  6. Step 6: Final answer
    x = 420.28

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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.