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Finding the Fourth Proportional to 209.66, 312.12 and 199.72

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Solution

The fourth proportional to 209.66, 312.12 and 199.72 is: 297.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.66 : 312.12 = 199.72 : x
  2. Step 2: Convert to fraction form
    209.66/312.12 = 199.72/x
  3. Step 3: Cross multiply
    209.66x = 312.12 × 199.72
  4. Step 4: Simplify right side
    209.66x = 62,334.40
  5. Step 5: Solve for x
    x = 62,334.40/209.66
  6. Step 6: Final answer
    x = 297.31

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.