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Finding the Fourth Proportional to 485.87, 670.28 and 309.02

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Solution

The fourth proportional to 485.87, 670.28 and 309.02 is: 426.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.87 : 670.28 = 309.02 : x
  2. Step 2: Convert to fraction form
    485.87/670.28 = 309.02/x
  3. Step 3: Cross multiply
    485.87x = 670.28 × 309.02
  4. Step 4: Simplify right side
    485.87x = 207,125.03
  5. Step 5: Solve for x
    x = 207,125.03/485.87
  6. Step 6: Final answer
    x = 426.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.