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Finding the Fourth Proportional to 853.61, 1,280.72 and 391.59

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Solution

The fourth proportional to 853.61, 1,280.72 and 391.59 is: 587.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.61 : 1,280.72 = 391.59 : x
  2. Step 2: Convert to fraction form
    853.61/1,280.72 = 391.59/x
  3. Step 3: Cross multiply
    853.61x = 1,280.72 × 391.59
  4. Step 4: Simplify right side
    853.61x = 501,518.12
  5. Step 5: Solve for x
    x = 501,518.12/853.61
  6. Step 6: Final answer
    x = 587.53

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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.