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Finding the Fourth Proportional to 660.19, 990.15 and 173.21

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Solution

The fourth proportional to 660.19, 990.15 and 173.21 is: 259.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.19 : 990.15 = 173.21 : x
  2. Step 2: Convert to fraction form
    660.19/990.15 = 173.21/x
  3. Step 3: Cross multiply
    660.19x = 990.15 × 173.21
  4. Step 4: Simplify right side
    660.19x = 171,503.88
  5. Step 5: Solve for x
    x = 171,503.88/660.19
  6. Step 6: Final answer
    x = 259.78

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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.