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Finding the Fourth Proportional to 663.49, 915.21 and 427.75

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Solution

The fourth proportional to 663.49, 915.21 and 427.75 is: 590.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.49 : 915.21 = 427.75 : x
  2. Step 2: Convert to fraction form
    663.49/915.21 = 427.75/x
  3. Step 3: Cross multiply
    663.49x = 915.21 × 427.75
  4. Step 4: Simplify right side
    663.49x = 391,481.08
  5. Step 5: Solve for x
    x = 391,481.08/663.49
  6. Step 6: Final answer
    x = 590.03

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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.