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Finding the Fourth Proportional to 67.31, 100.21 and 66.50

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Solution

The fourth proportional to 67.31, 100.21 and 66.50 is: 99.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.31 : 100.21 = 66.50 : x
  2. Step 2: Convert to fraction form
    67.31/100.21 = 66.50/x
  3. Step 3: Cross multiply
    67.31x = 100.21 × 66.50
  4. Step 4: Simplify right side
    67.31x = 6,663.30
  5. Step 5: Solve for x
    x = 6,663.30/67.31
  6. Step 6: Final answer
    x = 99.00

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.