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Finding the Fourth Proportional to 685.11, 1,026.99 and 319.58

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Solution

The fourth proportional to 685.11, 1,026.99 and 319.58 is: 479.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.11 : 1,026.99 = 319.58 : x
  2. Step 2: Convert to fraction form
    685.11/1,026.99 = 319.58/x
  3. Step 3: Cross multiply
    685.11x = 1,026.99 × 319.58
  4. Step 4: Simplify right side
    685.11x = 328,200.33
  5. Step 5: Solve for x
    x = 328,200.33/685.11
  6. Step 6: Final answer
    x = 479.05

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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.