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Finding the Fourth Proportional to 660.37, 990.36 and 221.55

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Solution

The fourth proportional to 660.37, 990.36 and 221.55 is: 332.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.37 : 990.36 = 221.55 : x
  2. Step 2: Convert to fraction form
    660.37/990.36 = 221.55/x
  3. Step 3: Cross multiply
    660.37x = 990.36 × 221.55
  4. Step 4: Simplify right side
    660.37x = 219,411.47
  5. Step 5: Solve for x
    x = 219,411.47/660.37
  6. Step 6: Final answer
    x = 332.25

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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.