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Finding the Fourth Proportional to 865.45, 1,297.88 and 280.35

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Solution

The fourth proportional to 865.45, 1,297.88 and 280.35 is: 420.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.45 : 1,297.88 = 280.35 : x
  2. Step 2: Convert to fraction form
    865.45/1,297.88 = 280.35/x
  3. Step 3: Cross multiply
    865.45x = 1,297.88 × 280.35
  4. Step 4: Simplify right side
    865.45x = 363,852.77
  5. Step 5: Solve for x
    x = 363,852.77/865.45
  6. Step 6: Final answer
    x = 420.42

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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.