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Finding the Fourth Proportional to 661.26, 992.70 and 418.80

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Solution

The fourth proportional to 661.26, 992.70 and 418.80 is: 628.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.26 : 992.70 = 418.80 : x
  2. Step 2: Convert to fraction form
    661.26/992.70 = 418.80/x
  3. Step 3: Cross multiply
    661.26x = 992.70 × 418.80
  4. Step 4: Simplify right side
    661.26x = 415,742.76
  5. Step 5: Solve for x
    x = 415,742.76/661.26
  6. Step 6: Final answer
    x = 628.71

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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.