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Finding the Fourth Proportional to 85.47, 118.05 and 57.79

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Solution

The fourth proportional to 85.47, 118.05 and 57.79 is: 79.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.47 : 118.05 = 57.79 : x
  2. Step 2: Convert to fraction form
    85.47/118.05 = 57.79/x
  3. Step 3: Cross multiply
    85.47x = 118.05 × 57.79
  4. Step 4: Simplify right side
    85.47x = 6,822.04
  5. Step 5: Solve for x
    x = 6,822.04/85.47
  6. Step 6: Final answer
    x = 79.82

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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.