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Finding the Fourth Proportional to 65.56, 90.48 and 39.70

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Solution

The fourth proportional to 65.56, 90.48 and 39.70 is: 54.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.56 : 90.48 = 39.70 : x
  2. Step 2: Convert to fraction form
    65.56/90.48 = 39.70/x
  3. Step 3: Cross multiply
    65.56x = 90.48 × 39.70
  4. Step 4: Simplify right side
    65.56x = 3,592.06
  5. Step 5: Solve for x
    x = 3,592.06/65.56
  6. Step 6: Final answer
    x = 54.79

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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.