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Finding the Fourth Proportional to 70.47, 97.61 and 65.21

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Solution

The fourth proportional to 70.47, 97.61 and 65.21 is: 90.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.47 : 97.61 = 65.21 : x
  2. Step 2: Convert to fraction form
    70.47/97.61 = 65.21/x
  3. Step 3: Cross multiply
    70.47x = 97.61 × 65.21
  4. Step 4: Simplify right side
    70.47x = 6,364.33
  5. Step 5: Solve for x
    x = 6,364.33/70.47
  6. Step 6: Final answer
    x = 90.31

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.