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Finding the Fourth Proportional to 85.52, 117.80 and 76.88

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Solution

The fourth proportional to 85.52, 117.80 and 76.88 is: 105.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.52 : 117.80 = 76.88 : x
  2. Step 2: Convert to fraction form
    85.52/117.80 = 76.88/x
  3. Step 3: Cross multiply
    85.52x = 117.80 × 76.88
  4. Step 4: Simplify right side
    85.52x = 9,056.46
  5. Step 5: Solve for x
    x = 9,056.46/85.52
  6. Step 6: Final answer
    x = 105.90

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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.