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Finding the Fourth Proportional to 259.20, 387.28 and 212.95

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Solution

The fourth proportional to 259.20, 387.28 and 212.95 is: 318.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.20 : 387.28 = 212.95 : x
  2. Step 2: Convert to fraction form
    259.20/387.28 = 212.95/x
  3. Step 3: Cross multiply
    259.20x = 387.28 × 212.95
  4. Step 4: Simplify right side
    259.20x = 82,473.12
  5. Step 5: Solve for x
    x = 82,473.12/259.20
  6. Step 6: Final answer
    x = 318.18

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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.