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Finding the Fourth Proportional to 497.79, 687 and 311.41

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Solution

The fourth proportional to 497.79, 687 and 311.41 is: 429.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    497.79 : 687 = 311.41 : x
  2. Step 2: Convert to fraction form
    497.79/687 = 311.41/x
  3. Step 3: Cross multiply
    497.79x = 687 × 311.41
  4. Step 4: Simplify right side
    497.79x = 213,938.67
  5. Step 5: Solve for x
    x = 213,938.67/497.79
  6. Step 6: Final answer
    x = 429.78

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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.