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Finding the Fourth Proportional to 684.80, 1,026.15 and 319.49

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Solution

The fourth proportional to 684.80, 1,026.15 and 319.49 is: 478.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.80 : 1,026.15 = 319.49 : x
  2. Step 2: Convert to fraction form
    684.80/1,026.15 = 319.49/x
  3. Step 3: Cross multiply
    684.80x = 1,026.15 × 319.49
  4. Step 4: Simplify right side
    684.80x = 327,839.53
  5. Step 5: Solve for x
    x = 327,839.53/684.80
  6. Step 6: Final answer
    x = 478.74

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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.