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Finding the Fourth Proportional to 663.53, 989.62 and 640.31

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Solution

The fourth proportional to 663.53, 989.62 and 640.31 is: 954.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.53 : 989.62 = 640.31 : x
  2. Step 2: Convert to fraction form
    663.53/989.62 = 640.31/x
  3. Step 3: Cross multiply
    663.53x = 989.62 × 640.31
  4. Step 4: Simplify right side
    663.53x = 633,657.03
  5. Step 5: Solve for x
    x = 633,657.03/663.53
  6. Step 6: Final answer
    x = 954.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.