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Finding the Fourth Proportional to 660.96, 989.28 and 415.80

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Solution

The fourth proportional to 660.96, 989.28 and 415.80 is: 622.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.96 : 989.28 = 415.80 : x
  2. Step 2: Convert to fraction form
    660.96/989.28 = 415.80/x
  3. Step 3: Cross multiply
    660.96x = 989.28 × 415.80
  4. Step 4: Simplify right side
    660.96x = 411,342.62
  5. Step 5: Solve for x
    x = 411,342.62/660.96
  6. Step 6: Final answer
    x = 622.34

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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.