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Finding the Fourth Proportional to 93.80, 129.38 and 77.40

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Solution

The fourth proportional to 93.80, 129.38 and 77.40 is: 106.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.80 : 129.38 = 77.40 : x
  2. Step 2: Convert to fraction form
    93.80/129.38 = 77.40/x
  3. Step 3: Cross multiply
    93.80x = 129.38 × 77.40
  4. Step 4: Simplify right side
    93.80x = 10,014.01
  5. Step 5: Solve for x
    x = 10,014.01/93.80
  6. Step 6: Final answer
    x = 106.76

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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.