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Finding the Fourth Proportional to 211.50, 317.25 and 89.85

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Solution

The fourth proportional to 211.50, 317.25 and 89.85 is: 134.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.50 : 317.25 = 89.85 : x
  2. Step 2: Convert to fraction form
    211.50/317.25 = 89.85/x
  3. Step 3: Cross multiply
    211.50x = 317.25 × 89.85
  4. Step 4: Simplify right side
    211.50x = 28,504.91
  5. Step 5: Solve for x
    x = 28,504.91/211.50
  6. Step 6: Final answer
    x = 134.78

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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.