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Finding the Fourth Proportional to 104.21, 143.79 and 65.38

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Solution

The fourth proportional to 104.21, 143.79 and 65.38 is: 90.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    104.21 : 143.79 = 65.38 : x
  2. Step 2: Convert to fraction form
    104.21/143.79 = 65.38/x
  3. Step 3: Cross multiply
    104.21x = 143.79 × 65.38
  4. Step 4: Simplify right side
    104.21x = 9,400.99
  5. Step 5: Solve for x
    x = 9,400.99/104.21
  6. Step 6: Final answer
    x = 90.21

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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.