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Finding the Fourth Proportional to 86.25, 129.42 and 70.23

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Solution

The fourth proportional to 86.25, 129.42 and 70.23 is: 105.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.25 : 129.42 = 70.23 : x
  2. Step 2: Convert to fraction form
    86.25/129.42 = 70.23/x
  3. Step 3: Cross multiply
    86.25x = 129.42 × 70.23
  4. Step 4: Simplify right side
    86.25x = 9,089.17
  5. Step 5: Solve for x
    x = 9,089.17/86.25
  6. Step 6: Final answer
    x = 105.38

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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.