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Finding the Fourth Proportional to 660.20, 990.40 and 243.76

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Solution

The fourth proportional to 660.20, 990.40 and 243.76 is: 365.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.20 : 990.40 = 243.76 : x
  2. Step 2: Convert to fraction form
    660.20/990.40 = 243.76/x
  3. Step 3: Cross multiply
    660.20x = 990.40 × 243.76
  4. Step 4: Simplify right side
    660.20x = 241,419.90
  5. Step 5: Solve for x
    x = 241,419.90/660.20
  6. Step 6: Final answer
    x = 365.68

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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.