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Finding the Fourth Proportional to 65.31, 90.21 and 51.64

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Solution

The fourth proportional to 65.31, 90.21 and 51.64 is: 71.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.31 : 90.21 = 51.64 : x
  2. Step 2: Convert to fraction form
    65.31/90.21 = 51.64/x
  3. Step 3: Cross multiply
    65.31x = 90.21 × 51.64
  4. Step 4: Simplify right side
    65.31x = 4,658.41
  5. Step 5: Solve for x
    x = 4,658.41/65.31
  6. Step 6: Final answer
    x = 71.33

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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.