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Finding the Fourth Proportional to 67.90, 102 and 57.79

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Solution

The fourth proportional to 67.90, 102 and 57.79 is: 86.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.90 : 102 = 57.79 : x
  2. Step 2: Convert to fraction form
    67.90/102 = 57.79/x
  3. Step 3: Cross multiply
    67.90x = 102 × 57.79
  4. Step 4: Simplify right side
    67.90x = 5,894.58
  5. Step 5: Solve for x
    x = 5,894.58/67.90
  6. Step 6: Final answer
    x = 86.81

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.