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Finding the Fourth Proportional to 660.79, 990.72 and 290.42

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Solution

The fourth proportional to 660.79, 990.72 and 290.42 is: 435.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.79 : 990.72 = 290.42 : x
  2. Step 2: Convert to fraction form
    660.79/990.72 = 290.42/x
  3. Step 3: Cross multiply
    660.79x = 990.72 × 290.42
  4. Step 4: Simplify right side
    660.79x = 287,724.90
  5. Step 5: Solve for x
    x = 287,724.90/660.79
  6. Step 6: Final answer
    x = 435.43

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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.