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Finding the Fourth Proportional to 853.50, 1,280.55 and 420.96

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Solution

The fourth proportional to 853.50, 1,280.55 and 420.96 is: 631.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.50 : 1,280.55 = 420.96 : x
  2. Step 2: Convert to fraction form
    853.50/1,280.55 = 420.96/x
  3. Step 3: Cross multiply
    853.50x = 1,280.55 × 420.96
  4. Step 4: Simplify right side
    853.50x = 539,060.33
  5. Step 5: Solve for x
    x = 539,060.33/853.50
  6. Step 6: Final answer
    x = 631.59

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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.