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Finding the Fourth Proportional to 78.07, 107.62 and 48.91

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Solution

The fourth proportional to 78.07, 107.62 and 48.91 is: 67.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.07 : 107.62 = 48.91 : x
  2. Step 2: Convert to fraction form
    78.07/107.62 = 48.91/x
  3. Step 3: Cross multiply
    78.07x = 107.62 × 48.91
  4. Step 4: Simplify right side
    78.07x = 5,263.69
  5. Step 5: Solve for x
    x = 5,263.69/78.07
  6. Step 6: Final answer
    x = 67.42

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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.