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Finding the Fourth Proportional to 209.55, 314.28 and 87.90

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Solution

The fourth proportional to 209.55, 314.28 and 87.90 is: 131.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.55 : 314.28 = 87.90 : x
  2. Step 2: Convert to fraction form
    209.55/314.28 = 87.90/x
  3. Step 3: Cross multiply
    209.55x = 314.28 × 87.90
  4. Step 4: Simplify right side
    209.55x = 27,625.21
  5. Step 5: Solve for x
    x = 27,625.21/209.55
  6. Step 6: Final answer
    x = 131.83

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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.