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Finding the Fourth Proportional to 71.21, 98.30 and 66.10

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Solution

The fourth proportional to 71.21, 98.30 and 66.10 is: 91.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.21 : 98.30 = 66.10 : x
  2. Step 2: Convert to fraction form
    71.21/98.30 = 66.10/x
  3. Step 3: Cross multiply
    71.21x = 98.30 × 66.10
  4. Step 4: Simplify right side
    71.21x = 6,497.63
  5. Step 5: Solve for x
    x = 6,497.63/71.21
  6. Step 6: Final answer
    x = 91.25

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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.