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Finding the Fourth Proportional to 103.58, 142.78 and 77.36

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Solution

The fourth proportional to 103.58, 142.78 and 77.36 is: 106.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.58 : 142.78 = 77.36 : x
  2. Step 2: Convert to fraction form
    103.58/142.78 = 77.36/x
  3. Step 3: Cross multiply
    103.58x = 142.78 × 77.36
  4. Step 4: Simplify right side
    103.58x = 11,045.46
  5. Step 5: Solve for x
    x = 11,045.46/103.58
  6. Step 6: Final answer
    x = 106.64

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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.