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Finding the Fourth Proportional to 684.40, 1,026.28 and 319.36

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Solution

The fourth proportional to 684.40, 1,026.28 and 319.36 is: 478.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.40 : 1,026.28 = 319.36 : x
  2. Step 2: Convert to fraction form
    684.40/1,026.28 = 319.36/x
  3. Step 3: Cross multiply
    684.40x = 1,026.28 × 319.36
  4. Step 4: Simplify right side
    684.40x = 327,752.78
  5. Step 5: Solve for x
    x = 327,752.78/684.40
  6. Step 6: Final answer
    x = 478.89

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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.