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Finding the Fourth Proportional to 109.78, 164.58 and 103.72

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Solution

The fourth proportional to 109.78, 164.58 and 103.72 is: 155.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.78 : 164.58 = 103.72 : x
  2. Step 2: Convert to fraction form
    109.78/164.58 = 103.72/x
  3. Step 3: Cross multiply
    109.78x = 164.58 × 103.72
  4. Step 4: Simplify right side
    109.78x = 17,070.24
  5. Step 5: Solve for x
    x = 17,070.24/109.78
  6. Step 6: Final answer
    x = 155.49

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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.