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Finding the Fourth Proportional to 498.29, 687.66 and 311.72

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Solution

The fourth proportional to 498.29, 687.66 and 311.72 is: 430.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.29 : 687.66 = 311.72 : x
  2. Step 2: Convert to fraction form
    498.29/687.66 = 311.72/x
  3. Step 3: Cross multiply
    498.29x = 687.66 × 311.72
  4. Step 4: Simplify right side
    498.29x = 214,357.65
  5. Step 5: Solve for x
    x = 214,357.65/498.29
  6. Step 6: Final answer
    x = 430.19

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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.