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Finding the Fourth Proportional to 109.45, 151.05 and 65.78

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Solution

The fourth proportional to 109.45, 151.05 and 65.78 is: 90.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.45 : 151.05 = 65.78 : x
  2. Step 2: Convert to fraction form
    109.45/151.05 = 65.78/x
  3. Step 3: Cross multiply
    109.45x = 151.05 × 65.78
  4. Step 4: Simplify right side
    109.45x = 9,934.98
  5. Step 5: Solve for x
    x = 9,934.98/109.45
  6. Step 6: Final answer
    x = 90.78

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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.