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Finding the Fourth Proportional to 88.20, 131.45 and 78.57

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Solution

The fourth proportional to 88.20, 131.45 and 78.57 is: 117.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.20 : 131.45 = 78.57 : x
  2. Step 2: Convert to fraction form
    88.20/131.45 = 78.57/x
  3. Step 3: Cross multiply
    88.20x = 131.45 × 78.57
  4. Step 4: Simplify right side
    88.20x = 10,327.63
  5. Step 5: Solve for x
    x = 10,327.63/88.20
  6. Step 6: Final answer
    x = 117.09

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.