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Finding the Fourth Proportional to 78.16, 107.72 and 56.29

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Solution

The fourth proportional to 78.16, 107.72 and 56.29 is: 77.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.16 : 107.72 = 56.29 : x
  2. Step 2: Convert to fraction form
    78.16/107.72 = 56.29/x
  3. Step 3: Cross multiply
    78.16x = 107.72 × 56.29
  4. Step 4: Simplify right side
    78.16x = 6,063.28
  5. Step 5: Solve for x
    x = 6,063.28/78.16
  6. Step 6: Final answer
    x = 77.58

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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.