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Finding the Fourth Proportional to 89.78, 134.53 and 79.65

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Solution

The fourth proportional to 89.78, 134.53 and 79.65 is: 119.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.78 : 134.53 = 79.65 : x
  2. Step 2: Convert to fraction form
    89.78/134.53 = 79.65/x
  3. Step 3: Cross multiply
    89.78x = 134.53 × 79.65
  4. Step 4: Simplify right side
    89.78x = 10,715.12
  5. Step 5: Solve for x
    x = 10,715.12/89.78
  6. Step 6: Final answer
    x = 119.36

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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.