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Finding the Fourth Proportional to 547.80, 820.80 and 515.40

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Solution

The fourth proportional to 547.80, 820.80 and 515.40 is: 772.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    547.80 : 820.80 = 515.40 : x
  2. Step 2: Convert to fraction form
    547.80/820.80 = 515.40/x
  3. Step 3: Cross multiply
    547.80x = 820.80 × 515.40
  4. Step 4: Simplify right side
    547.80x = 423,040.32
  5. Step 5: Solve for x
    x = 423,040.32/547.80
  6. Step 6: Final answer
    x = 772.25

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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.