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Finding the Fourth Proportional to 497.10, 685.85 and 310.78

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Solution

The fourth proportional to 497.10, 685.85 and 310.78 is: 428.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    497.10 : 685.85 = 310.78 : x
  2. Step 2: Convert to fraction form
    497.10/685.85 = 310.78/x
  3. Step 3: Cross multiply
    497.10x = 685.85 × 310.78
  4. Step 4: Simplify right side
    497.10x = 213,145.81
  5. Step 5: Solve for x
    x = 213,145.81/497.10
  6. Step 6: Final answer
    x = 428.78

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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.