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Finding the Fourth Proportional to 813.29, 1,217.09 and 665.33

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Solution

The fourth proportional to 813.29, 1,217.09 and 665.33 is: 995.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.29 : 1,217.09 = 665.33 : x
  2. Step 2: Convert to fraction form
    813.29/1,217.09 = 665.33/x
  3. Step 3: Cross multiply
    813.29x = 1,217.09 × 665.33
  4. Step 4: Simplify right side
    813.29x = 809,762.07
  5. Step 5: Solve for x
    x = 809,762.07/813.29
  6. Step 6: Final answer
    x = 995.67

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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.