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Finding the Fourth Proportional to 98.02, 135.42 and 78.58

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Solution

The fourth proportional to 98.02, 135.42 and 78.58 is: 108.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.02 : 135.42 = 78.58 : x
  2. Step 2: Convert to fraction form
    98.02/135.42 = 78.58/x
  3. Step 3: Cross multiply
    98.02x = 135.42 × 78.58
  4. Step 4: Simplify right side
    98.02x = 10,641.30
  5. Step 5: Solve for x
    x = 10,641.30/98.02
  6. Step 6: Final answer
    x = 108.56

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.