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Finding the Fourth Proportional to 265.20, 397.80 and 72.80

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Solution

The fourth proportional to 265.20, 397.80 and 72.80 is: 109.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.20 : 397.80 = 72.80 : x
  2. Step 2: Convert to fraction form
    265.20/397.80 = 72.80/x
  3. Step 3: Cross multiply
    265.20x = 397.80 × 72.80
  4. Step 4: Simplify right side
    265.20x = 28,959.84
  5. Step 5: Solve for x
    x = 28,959.84/265.20
  6. Step 6: Final answer
    x = 109.20

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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.