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Finding the Fourth Proportional to 811.45, 1,217.49 and 656.71

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Solution

The fourth proportional to 811.45, 1,217.49 and 656.71 is: 985.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.45 : 1,217.49 = 656.71 : x
  2. Step 2: Convert to fraction form
    811.45/1,217.49 = 656.71/x
  3. Step 3: Cross multiply
    811.45x = 1,217.49 × 656.71
  4. Step 4: Simplify right side
    811.45x = 799,531.77
  5. Step 5: Solve for x
    x = 799,531.77/811.45
  6. Step 6: Final answer
    x = 985.31

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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.