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Finding the Fourth Proportional to 85.91, 118.55 and 47.09

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Solution

The fourth proportional to 85.91, 118.55 and 47.09 is: 64.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.91 : 118.55 = 47.09 : x
  2. Step 2: Convert to fraction form
    85.91/118.55 = 47.09/x
  3. Step 3: Cross multiply
    85.91x = 118.55 × 47.09
  4. Step 4: Simplify right side
    85.91x = 5,582.99
  5. Step 5: Solve for x
    x = 5,582.99/85.91
  6. Step 6: Final answer
    x = 64.99

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.