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Finding the Fourth Proportional to 321.71, 482.79 and 139.23

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Solution

The fourth proportional to 321.71, 482.79 and 139.23 is: 208.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.71 : 482.79 = 139.23 : x
  2. Step 2: Convert to fraction form
    321.71/482.79 = 139.23/x
  3. Step 3: Cross multiply
    321.71x = 482.79 × 139.23
  4. Step 4: Simplify right side
    321.71x = 67,218.85
  5. Step 5: Solve for x
    x = 67,218.85/321.71
  6. Step 6: Final answer
    x = 208.94

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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.