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Finding the Fourth Proportional to 71.12, 98 and 65.20

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Solution

The fourth proportional to 71.12, 98 and 65.20 is: 89.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.12 : 98 = 65.20 : x
  2. Step 2: Convert to fraction form
    71.12/98 = 65.20/x
  3. Step 3: Cross multiply
    71.12x = 98 × 65.20
  4. Step 4: Simplify right side
    71.12x = 6,389.60
  5. Step 5: Solve for x
    x = 6,389.60/71.12
  6. Step 6: Final answer
    x = 89.84

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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.