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Finding the Fourth Proportional to 85.48, 117.90 and 69.28

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Solution

The fourth proportional to 85.48, 117.90 and 69.28 is: 95.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.48 : 117.90 = 69.28 : x
  2. Step 2: Convert to fraction form
    85.48/117.90 = 69.28/x
  3. Step 3: Cross multiply
    85.48x = 117.90 × 69.28
  4. Step 4: Simplify right side
    85.48x = 8,168.11
  5. Step 5: Solve for x
    x = 8,168.11/85.48
  6. Step 6: Final answer
    x = 95.56

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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.