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Finding the Fourth Proportional to 209.06, 313.48 and 87.18

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Solution

The fourth proportional to 209.06, 313.48 and 87.18 is: 130.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.06 : 313.48 = 87.18 : x
  2. Step 2: Convert to fraction form
    209.06/313.48 = 87.18/x
  3. Step 3: Cross multiply
    209.06x = 313.48 × 87.18
  4. Step 4: Simplify right side
    209.06x = 27,329.19
  5. Step 5: Solve for x
    x = 27,329.19/209.06
  6. Step 6: Final answer
    x = 130.72

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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.