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Finding the Fourth Proportional to 498.69, 687.92 and 288.79

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Solution

The fourth proportional to 498.69, 687.92 and 288.79 is: 398.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.69 : 687.92 = 288.79 : x
  2. Step 2: Convert to fraction form
    498.69/687.92 = 288.79/x
  3. Step 3: Cross multiply
    498.69x = 687.92 × 288.79
  4. Step 4: Simplify right side
    498.69x = 198,661.25
  5. Step 5: Solve for x
    x = 198,661.25/498.69
  6. Step 6: Final answer
    x = 398.37

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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.