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Finding the Fourth Proportional to 72.45, 108.36 and 70.49

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Solution

The fourth proportional to 72.45, 108.36 and 70.49 is: 105.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.45 : 108.36 = 70.49 : x
  2. Step 2: Convert to fraction form
    72.45/108.36 = 70.49/x
  3. Step 3: Cross multiply
    72.45x = 108.36 × 70.49
  4. Step 4: Simplify right side
    72.45x = 7,637.75
  5. Step 5: Solve for x
    x = 7,637.75/72.45
  6. Step 6: Final answer
    x = 105.42

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.