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Finding the Fourth Proportional to 127.86, 176.38 and 78.71

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Solution

The fourth proportional to 127.86, 176.38 and 78.71 is: 108.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.86 : 176.38 = 78.71 : x
  2. Step 2: Convert to fraction form
    127.86/176.38 = 78.71/x
  3. Step 3: Cross multiply
    127.86x = 176.38 × 78.71
  4. Step 4: Simplify right side
    127.86x = 13,881.99
  5. Step 5: Solve for x
    x = 13,881.99/127.86
  6. Step 6: Final answer
    x = 108.58

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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.