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Finding the Fourth Proportional to 321.93, 482.79 and 139.21

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Solution

The fourth proportional to 321.93, 482.79 and 139.21 is: 208.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.93 : 482.79 = 139.21 : x
  2. Step 2: Convert to fraction form
    321.93/482.79 = 139.21/x
  3. Step 3: Cross multiply
    321.93x = 482.79 × 139.21
  4. Step 4: Simplify right side
    321.93x = 67,209.20
  5. Step 5: Solve for x
    x = 67,209.20/321.93
  6. Step 6: Final answer
    x = 208.77

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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.