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Finding the Fourth Proportional to 685.80, 1,029.19 and 275.05

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Solution

The fourth proportional to 685.80, 1,029.19 and 275.05 is: 412.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.80 : 1,029.19 = 275.05 : x
  2. Step 2: Convert to fraction form
    685.80/1,029.19 = 275.05/x
  3. Step 3: Cross multiply
    685.80x = 1,029.19 × 275.05
  4. Step 4: Simplify right side
    685.80x = 283,078.71
  5. Step 5: Solve for x
    x = 283,078.71/685.80
  6. Step 6: Final answer
    x = 412.77

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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.