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Finding the Fourth Proportional to 684.19, 1,026.29 and 318.78

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Solution

The fourth proportional to 684.19, 1,026.29 and 318.78 is: 478.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.19 : 1,026.29 = 318.78 : x
  2. Step 2: Convert to fraction form
    684.19/1,026.29 = 318.78/x
  3. Step 3: Cross multiply
    684.19x = 1,026.29 × 318.78
  4. Step 4: Simplify right side
    684.19x = 327,160.73
  5. Step 5: Solve for x
    x = 327,160.73/684.19
  6. Step 6: Final answer
    x = 478.17

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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.