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Finding the Fourth Proportional to 82.78, 114.28 and 78.32

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Solution

The fourth proportional to 82.78, 114.28 and 78.32 is: 108.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.78 : 114.28 = 78.32 : x
  2. Step 2: Convert to fraction form
    82.78/114.28 = 78.32/x
  3. Step 3: Cross multiply
    82.78x = 114.28 × 78.32
  4. Step 4: Simplify right side
    82.78x = 8,950.50
  5. Step 5: Solve for x
    x = 8,950.50/82.78
  6. Step 6: Final answer
    x = 108.13

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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.