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Finding the Fourth Proportional to 853.85, 1,280.78 and 306.20

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Solution

The fourth proportional to 853.85, 1,280.78 and 306.20 is: 459.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.85 : 1,280.78 = 306.20 : x
  2. Step 2: Convert to fraction form
    853.85/1,280.78 = 306.20/x
  3. Step 3: Cross multiply
    853.85x = 1,280.78 × 306.20
  4. Step 4: Simplify right side
    853.85x = 392,169.20
  5. Step 5: Solve for x
    x = 392,169.20/853.85
  6. Step 6: Final answer
    x = 459.29

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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.