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Finding the Fourth Proportional to 78.69, 108.49 and 51.06

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Solution

The fourth proportional to 78.69, 108.49 and 51.06 is: 70.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.69 : 108.49 = 51.06 : x
  2. Step 2: Convert to fraction form
    78.69/108.49 = 51.06/x
  3. Step 3: Cross multiply
    78.69x = 108.49 × 51.06
  4. Step 4: Simplify right side
    78.69x = 5,539.24
  5. Step 5: Solve for x
    x = 5,539.24/78.69
  6. Step 6: Final answer
    x = 70.39

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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.