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Finding the Fourth Proportional to 89.81, 135.24 and 78.53

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Solution

The fourth proportional to 89.81, 135.24 and 78.53 is: 118.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.81 : 135.24 = 78.53 : x
  2. Step 2: Convert to fraction form
    89.81/135.24 = 78.53/x
  3. Step 3: Cross multiply
    89.81x = 135.24 × 78.53
  4. Step 4: Simplify right side
    89.81x = 10,620.40
  5. Step 5: Solve for x
    x = 10,620.40/89.81
  6. Step 6: Final answer
    x = 118.25

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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.