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Finding the Fourth Proportional to 105.79, 158.47 and 87.70

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Solution

The fourth proportional to 105.79, 158.47 and 87.70 is: 131.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.79 : 158.47 = 87.70 : x
  2. Step 2: Convert to fraction form
    105.79/158.47 = 87.70/x
  3. Step 3: Cross multiply
    105.79x = 158.47 × 87.70
  4. Step 4: Simplify right side
    105.79x = 13,897.82
  5. Step 5: Solve for x
    x = 13,897.82/105.79
  6. Step 6: Final answer
    x = 131.37

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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.