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Finding the Fourth Proportional to 865.30, 1,297.56 and 280.20

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Solution

The fourth proportional to 865.30, 1,297.56 and 280.20 is: 420.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.30 : 1,297.56 = 280.20 : x
  2. Step 2: Convert to fraction form
    865.30/1,297.56 = 280.20/x
  3. Step 3: Cross multiply
    865.30x = 1,297.56 × 280.20
  4. Step 4: Simplify right side
    865.30x = 363,576.31
  5. Step 5: Solve for x
    x = 363,576.31/865.30
  6. Step 6: Final answer
    x = 420.17

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1.5x scale

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.