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Finding the Fourth Proportional to 660.64, 990.29 and 429.99

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Solution

The fourth proportional to 660.64, 990.29 and 429.99 is: 644.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.64 : 990.29 = 429.99 : x
  2. Step 2: Convert to fraction form
    660.64/990.29 = 429.99/x
  3. Step 3: Cross multiply
    660.64x = 990.29 × 429.99
  4. Step 4: Simplify right side
    660.64x = 425,815.12
  5. Step 5: Solve for x
    x = 425,815.12/660.64
  6. Step 6: Final answer
    x = 644.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.