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Finding the Fourth Proportional to 107.78, 148.72 and 78.28

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Solution

The fourth proportional to 107.78, 148.72 and 78.28 is: 108.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    107.78 : 148.72 = 78.28 : x
  2. Step 2: Convert to fraction form
    107.78/148.72 = 78.28/x
  3. Step 3: Cross multiply
    107.78x = 148.72 × 78.28
  4. Step 4: Simplify right side
    107.78x = 11,641.80
  5. Step 5: Solve for x
    x = 11,641.80/107.78
  6. Step 6: Final answer
    x = 108.01

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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.