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Finding the Fourth Proportional to 78.88, 108.69 and 70.61

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Solution

The fourth proportional to 78.88, 108.69 and 70.61 is: 97.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.88 : 108.69 = 70.61 : x
  2. Step 2: Convert to fraction form
    78.88/108.69 = 70.61/x
  3. Step 3: Cross multiply
    78.88x = 108.69 × 70.61
  4. Step 4: Simplify right side
    78.88x = 7,674.60
  5. Step 5: Solve for x
    x = 7,674.60/78.88
  6. Step 6: Final answer
    x = 97.29

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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.