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Finding the Fourth Proportional to 102.74, 153.98 and 78.58

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Solution

The fourth proportional to 102.74, 153.98 and 78.58 is: 117.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.74 : 153.98 = 78.58 : x
  2. Step 2: Convert to fraction form
    102.74/153.98 = 78.58/x
  3. Step 3: Cross multiply
    102.74x = 153.98 × 78.58
  4. Step 4: Simplify right side
    102.74x = 12,098.76
  5. Step 5: Solve for x
    x = 12,098.76/102.74
  6. Step 6: Final answer
    x = 117.76

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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.