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Finding the Fourth Proportional to 280.75, 420.85 and 189.47

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Solution

The fourth proportional to 280.75, 420.85 and 189.47 is: 284.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.75 : 420.85 = 189.47 : x
  2. Step 2: Convert to fraction form
    280.75/420.85 = 189.47/x
  3. Step 3: Cross multiply
    280.75x = 420.85 × 189.47
  4. Step 4: Simplify right side
    280.75x = 79,738.45
  5. Step 5: Solve for x
    x = 79,738.45/280.75
  6. Step 6: Final answer
    x = 284.02

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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.