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Finding the Fourth Proportional to 660.66, 990.30 and 221.58

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Solution

The fourth proportional to 660.66, 990.30 and 221.58 is: 332.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.66 : 990.30 = 221.58 : x
  2. Step 2: Convert to fraction form
    660.66/990.30 = 221.58/x
  3. Step 3: Cross multiply
    660.66x = 990.30 × 221.58
  4. Step 4: Simplify right side
    660.66x = 219,435.22
  5. Step 5: Solve for x
    x = 219,435.22/660.66
  6. Step 6: Final answer
    x = 332.15

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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.