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Finding the Fourth Proportional to 661.80, 992.07 and 387.84

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Solution

The fourth proportional to 661.80, 992.07 and 387.84 is: 581.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.80 : 992.07 = 387.84 : x
  2. Step 2: Convert to fraction form
    661.80/992.07 = 387.84/x
  3. Step 3: Cross multiply
    661.80x = 992.07 × 387.84
  4. Step 4: Simplify right side
    661.80x = 384,764.43
  5. Step 5: Solve for x
    x = 384,764.43/661.80
  6. Step 6: Final answer
    x = 581.39

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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.