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Finding the Fourth Proportional to 660.35, 990.87 and 429.18

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Solution

The fourth proportional to 660.35, 990.87 and 429.18 is: 644.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.35 : 990.87 = 429.18 : x
  2. Step 2: Convert to fraction form
    660.35/990.87 = 429.18/x
  3. Step 3: Cross multiply
    660.35x = 990.87 × 429.18
  4. Step 4: Simplify right side
    660.35x = 425,261.59
  5. Step 5: Solve for x
    x = 425,261.59/660.35
  6. Step 6: Final answer
    x = 644.00

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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.