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Finding the Fourth Proportional to 318.40, 479.72 and 275.20

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Solution

The fourth proportional to 318.40, 479.72 and 275.20 is: 414.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.40 : 479.72 = 275.20 : x
  2. Step 2: Convert to fraction form
    318.40/479.72 = 275.20/x
  3. Step 3: Cross multiply
    318.40x = 479.72 × 275.20
  4. Step 4: Simplify right side
    318.40x = 132,018.94
  5. Step 5: Solve for x
    x = 132,018.94/318.40
  6. Step 6: Final answer
    x = 414.63

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.