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Finding the Fourth Proportional to 498.40, 687.60 and 291.28

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Solution

The fourth proportional to 498.40, 687.60 and 291.28 is: 401.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.40 : 687.60 = 291.28 : x
  2. Step 2: Convert to fraction form
    498.40/687.60 = 291.28/x
  3. Step 3: Cross multiply
    498.40x = 687.60 × 291.28
  4. Step 4: Simplify right side
    498.40x = 200,284.13
  5. Step 5: Solve for x
    x = 200,284.13/498.40
  6. Step 6: Final answer
    x = 401.85

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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.