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Finding the Fourth Proportional to 103.40, 154.45 and 87.40

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Solution

The fourth proportional to 103.40, 154.45 and 87.40 is: 130.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.40 : 154.45 = 87.40 : x
  2. Step 2: Convert to fraction form
    103.40/154.45 = 87.40/x
  3. Step 3: Cross multiply
    103.40x = 154.45 × 87.40
  4. Step 4: Simplify right side
    103.40x = 13,498.93
  5. Step 5: Solve for x
    x = 13,498.93/103.40
  6. Step 6: Final answer
    x = 130.55

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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.