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Finding the Fourth Proportional to 85.24, 128.13 and 51.07

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Solution

The fourth proportional to 85.24, 128.13 and 51.07 is: 76.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.24 : 128.13 = 51.07 : x
  2. Step 2: Convert to fraction form
    85.24/128.13 = 51.07/x
  3. Step 3: Cross multiply
    85.24x = 128.13 × 51.07
  4. Step 4: Simplify right side
    85.24x = 6,543.60
  5. Step 5: Solve for x
    x = 6,543.60/85.24
  6. Step 6: Final answer
    x = 76.77

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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.