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Finding the Fourth Proportional to 661.02, 989.10 and 387.24

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Solution

The fourth proportional to 661.02, 989.10 and 387.24 is: 579.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.02 : 989.10 = 387.24 : x
  2. Step 2: Convert to fraction form
    661.02/989.10 = 387.24/x
  3. Step 3: Cross multiply
    661.02x = 989.10 × 387.24
  4. Step 4: Simplify right side
    661.02x = 383,019.08
  5. Step 5: Solve for x
    x = 383,019.08/661.02
  6. Step 6: Final answer
    x = 579.44

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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.