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Finding the Fourth Proportional to 321.12, 479.64 and 285.28

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Solution

The fourth proportional to 321.12, 479.64 and 285.28 is: 426.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.12 : 479.64 = 285.28 : x
  2. Step 2: Convert to fraction form
    321.12/479.64 = 285.28/x
  3. Step 3: Cross multiply
    321.12x = 479.64 × 285.28
  4. Step 4: Simplify right side
    321.12x = 136,831.70
  5. Step 5: Solve for x
    x = 136,831.70/321.12
  6. Step 6: Final answer
    x = 426.11

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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.