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Finding the Fourth Proportional to 211.86, 317.81 and 120.60

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Solution

The fourth proportional to 211.86, 317.81 and 120.60 is: 180.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.86 : 317.81 = 120.60 : x
  2. Step 2: Convert to fraction form
    211.86/317.81 = 120.60/x
  3. Step 3: Cross multiply
    211.86x = 317.81 × 120.60
  4. Step 4: Simplify right side
    211.86x = 38,327.28
  5. Step 5: Solve for x
    x = 38,327.28/211.86
  6. Step 6: Final answer
    x = 180.91

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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.