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Finding the Fourth Proportional to 85.12, 127.56 and 42.28

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Solution

The fourth proportional to 85.12, 127.56 and 42.28 is: 63.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.12 : 127.56 = 42.28 : x
  2. Step 2: Convert to fraction form
    85.12/127.56 = 42.28/x
  3. Step 3: Cross multiply
    85.12x = 127.56 × 42.28
  4. Step 4: Simplify right side
    85.12x = 5,393.24
  5. Step 5: Solve for x
    x = 5,393.24/85.12
  6. Step 6: Final answer
    x = 63.36

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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.