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Finding the Fourth Proportional to 660.42, 990.80 and 198.18

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Solution

The fourth proportional to 660.42, 990.80 and 198.18 is: 297.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.42 : 990.80 = 198.18 : x
  2. Step 2: Convert to fraction form
    660.42/990.80 = 198.18/x
  3. Step 3: Cross multiply
    660.42x = 990.80 × 198.18
  4. Step 4: Simplify right side
    660.42x = 196,356.74
  5. Step 5: Solve for x
    x = 196,356.74/660.42
  6. Step 6: Final answer
    x = 297.32

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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.