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Finding the Fourth Proportional to 85.08, 128.28 and 79.14

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Solution

The fourth proportional to 85.08, 128.28 and 79.14 is: 119.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.08 : 128.28 = 79.14 : x
  2. Step 2: Convert to fraction form
    85.08/128.28 = 79.14/x
  3. Step 3: Cross multiply
    85.08x = 128.28 × 79.14
  4. Step 4: Simplify right side
    85.08x = 10,152.08
  5. Step 5: Solve for x
    x = 10,152.08/85.08
  6. Step 6: Final answer
    x = 119.32

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.