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Finding the Fourth Proportional to 71.60, 98.70 and 66.20

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Solution

The fourth proportional to 71.60, 98.70 and 66.20 is: 91.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.60 : 98.70 = 66.20 : x
  2. Step 2: Convert to fraction form
    71.60/98.70 = 66.20/x
  3. Step 3: Cross multiply
    71.60x = 98.70 × 66.20
  4. Step 4: Simplify right side
    71.60x = 6,533.94
  5. Step 5: Solve for x
    x = 6,533.94/71.60
  6. Step 6: Final answer
    x = 91.26

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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.