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Finding the Fourth Proportional to 85.36, 128.04 and 53.26

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Solution

The fourth proportional to 85.36, 128.04 and 53.26 is: 79.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.36 : 128.04 = 53.26 : x
  2. Step 2: Convert to fraction form
    85.36/128.04 = 53.26/x
  3. Step 3: Cross multiply
    85.36x = 128.04 × 53.26
  4. Step 4: Simplify right side
    85.36x = 6,819.41
  5. Step 5: Solve for x
    x = 6,819.41/85.36
  6. Step 6: Final answer
    x = 79.89

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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.