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Finding the Fourth Proportional to 687.90, 942.87 and 663.30

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Solution

The fourth proportional to 687.90, 942.87 and 663.30 is: 909.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.90 : 942.87 = 663.30 : x
  2. Step 2: Convert to fraction form
    687.90/942.87 = 663.30/x
  3. Step 3: Cross multiply
    687.90x = 942.87 × 663.30
  4. Step 4: Simplify right side
    687.90x = 625,405.67
  5. Step 5: Solve for x
    x = 625,405.67/687.90
  6. Step 6: Final answer
    x = 909.15

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.