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Finding the Fourth Proportional to 487.86, 731.99 and 213.81

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Solution

The fourth proportional to 487.86, 731.99 and 213.81 is: 320.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.86 : 731.99 = 213.81 : x
  2. Step 2: Convert to fraction form
    487.86/731.99 = 213.81/x
  3. Step 3: Cross multiply
    487.86x = 731.99 × 213.81
  4. Step 4: Simplify right side
    487.86x = 156,506.78
  5. Step 5: Solve for x
    x = 156,506.78/487.86
  6. Step 6: Final answer
    x = 320.80

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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.