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Finding the Fourth Proportional to 660.41, 990.29 and 221.51

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Solution

The fourth proportional to 660.41, 990.29 and 221.51 is: 332.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.41 : 990.29 = 221.51 : x
  2. Step 2: Convert to fraction form
    660.41/990.29 = 221.51/x
  3. Step 3: Cross multiply
    660.41x = 990.29 × 221.51
  4. Step 4: Simplify right side
    660.41x = 219,359.14
  5. Step 5: Solve for x
    x = 219,359.14/660.41
  6. Step 6: Final answer
    x = 332.16

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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.