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Finding the Fourth Proportional to 318.69, 478.12 and 145.28

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Solution

The fourth proportional to 318.69, 478.12 and 145.28 is: 217.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.69 : 478.12 = 145.28 : x
  2. Step 2: Convert to fraction form
    318.69/478.12 = 145.28/x
  3. Step 3: Cross multiply
    318.69x = 478.12 × 145.28
  4. Step 4: Simplify right side
    318.69x = 69,458.52
  5. Step 5: Solve for x
    x = 69,458.52/318.69
  6. Step 6: Final answer
    x = 217.95

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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.