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Finding the Fourth Proportional to 660.69, 991.08 and 221.99

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Solution

The fourth proportional to 660.69, 991.08 and 221.99 is: 332.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.69 : 991.08 = 221.99 : x
  2. Step 2: Convert to fraction form
    660.69/991.08 = 221.99/x
  3. Step 3: Cross multiply
    660.69x = 991.08 × 221.99
  4. Step 4: Simplify right side
    660.69x = 220,004.89
  5. Step 5: Solve for x
    x = 220,004.89/660.69
  6. Step 6: Final answer
    x = 332.99

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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.