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Finding the Fourth Proportional to 209.83, 314.65 and 86.34

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Solution

The fourth proportional to 209.83, 314.65 and 86.34 is: 129.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.83 : 314.65 = 86.34 : x
  2. Step 2: Convert to fraction form
    209.83/314.65 = 86.34/x
  3. Step 3: Cross multiply
    209.83x = 314.65 × 86.34
  4. Step 4: Simplify right side
    209.83x = 27,167.45
  5. Step 5: Solve for x
    x = 27,167.45/209.83
  6. Step 6: Final answer
    x = 129.48

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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.