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Finding the Fourth Proportional to 85.11, 127.65 and 39.45

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Solution

The fourth proportional to 85.11, 127.65 and 39.45 is: 59.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.11 : 127.65 = 39.45 : x
  2. Step 2: Convert to fraction form
    85.11/127.65 = 39.45/x
  3. Step 3: Cross multiply
    85.11x = 127.65 × 39.45
  4. Step 4: Simplify right side
    85.11x = 5,035.79
  5. Step 5: Solve for x
    x = 5,035.79/85.11
  6. Step 6: Final answer
    x = 59.17

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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.