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Finding the Fourth Proportional to 85.24, 128.09 and 52.75

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Solution

The fourth proportional to 85.24, 128.09 and 52.75 is: 79.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.24 : 128.09 = 52.75 : x
  2. Step 2: Convert to fraction form
    85.24/128.09 = 52.75/x
  3. Step 3: Cross multiply
    85.24x = 128.09 × 52.75
  4. Step 4: Simplify right side
    85.24x = 6,756.75
  5. Step 5: Solve for x
    x = 6,756.75/85.24
  6. Step 6: Final answer
    x = 79.27

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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.