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Finding the Fourth Proportional to 109.47, 151.28 and 78.49

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Solution

The fourth proportional to 109.47, 151.28 and 78.49 is: 108.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.47 : 151.28 = 78.49 : x
  2. Step 2: Convert to fraction form
    109.47/151.28 = 78.49/x
  3. Step 3: Cross multiply
    109.47x = 151.28 × 78.49
  4. Step 4: Simplify right side
    109.47x = 11,873.57
  5. Step 5: Solve for x
    x = 11,873.57/109.47
  6. Step 6: Final answer
    x = 108.46

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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.