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Finding the Fourth Proportional to 853.81, 1,280.20 and 458.71

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Solution

The fourth proportional to 853.81, 1,280.20 and 458.71 is: 687.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.81 : 1,280.20 = 458.71 : x
  2. Step 2: Convert to fraction form
    853.81/1,280.20 = 458.71/x
  3. Step 3: Cross multiply
    853.81x = 1,280.20 × 458.71
  4. Step 4: Simplify right side
    853.81x = 587,240.54
  5. Step 5: Solve for x
    x = 587,240.54/853.81
  6. Step 6: Final answer
    x = 687.79

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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.