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Finding the Fourth Proportional to 104.19, 143.78 and 64.90

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Solution

The fourth proportional to 104.19, 143.78 and 64.90 is: 89.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    104.19 : 143.78 = 64.90 : x
  2. Step 2: Convert to fraction form
    104.19/143.78 = 64.90/x
  3. Step 3: Cross multiply
    104.19x = 143.78 × 64.90
  4. Step 4: Simplify right side
    104.19x = 9,331.32
  5. Step 5: Solve for x
    x = 9,331.32/104.19
  6. Step 6: Final answer
    x = 89.56

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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.