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Finding the Fourth Proportional to 321.62, 479.95 and 287.12

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Solution

The fourth proportional to 321.62, 479.95 and 287.12 is: 428.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.62 : 479.95 = 287.12 : x
  2. Step 2: Convert to fraction form
    321.62/479.95 = 287.12/x
  3. Step 3: Cross multiply
    321.62x = 479.95 × 287.12
  4. Step 4: Simplify right side
    321.62x = 137,803.18
  5. Step 5: Solve for x
    x = 137,803.18/321.62
  6. Step 6: Final answer
    x = 428.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.