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Finding the Fourth Proportional to 660.40, 990.78 and 372.04

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Solution

The fourth proportional to 660.40, 990.78 and 372.04 is: 558.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.40 : 990.78 = 372.04 : x
  2. Step 2: Convert to fraction form
    660.40/990.78 = 372.04/x
  3. Step 3: Cross multiply
    660.40x = 990.78 × 372.04
  4. Step 4: Simplify right side
    660.40x = 368,609.79
  5. Step 5: Solve for x
    x = 368,609.79/660.40
  6. Step 6: Final answer
    x = 558.16

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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.