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Finding the Fourth Proportional to 498.47, 687.78 and 288.63

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Solution

The fourth proportional to 498.47, 687.78 and 288.63 is: 398.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.47 : 687.78 = 288.63 : x
  2. Step 2: Convert to fraction form
    498.47/687.78 = 288.63/x
  3. Step 3: Cross multiply
    498.47x = 687.78 × 288.63
  4. Step 4: Simplify right side
    498.47x = 198,511.57
  5. Step 5: Solve for x
    x = 198,511.57/498.47
  6. Step 6: Final answer
    x = 398.25

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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.