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Finding the Fourth Proportional to 64.90, 97.30 and 21.55

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Solution

The fourth proportional to 64.90, 97.30 and 21.55 is: 32.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.90 : 97.30 = 21.55 : x
  2. Step 2: Convert to fraction form
    64.90/97.30 = 21.55/x
  3. Step 3: Cross multiply
    64.90x = 97.30 × 21.55
  4. Step 4: Simplify right side
    64.90x = 2,096.82
  5. Step 5: Solve for x
    x = 2,096.82/64.90
  6. Step 6: Final answer
    x = 32.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.