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Finding the Fourth Proportional to 75.78, 104.63 and 66.13

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Solution

The fourth proportional to 75.78, 104.63 and 66.13 is: 91.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.78 : 104.63 = 66.13 : x
  2. Step 2: Convert to fraction form
    75.78/104.63 = 66.13/x
  3. Step 3: Cross multiply
    75.78x = 104.63 × 66.13
  4. Step 4: Simplify right side
    75.78x = 6,918.59
  5. Step 5: Solve for x
    x = 6,918.59/75.78
  6. Step 6: Final answer
    x = 91.30

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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.