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Finding the Fourth Proportional to 930.12, 1,395.21 and 280.86

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Solution

The fourth proportional to 930.12, 1,395.21 and 280.86 is: 421.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    930.12 : 1,395.21 = 280.86 : x
  2. Step 2: Convert to fraction form
    930.12/1,395.21 = 280.86/x
  3. Step 3: Cross multiply
    930.12x = 1,395.21 × 280.86
  4. Step 4: Simplify right side
    930.12x = 391,858.68
  5. Step 5: Solve for x
    x = 391,858.68/930.12
  6. Step 6: Final answer
    x = 421.30

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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.