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Finding the Fourth Proportional to 65.20, 89.86 and 56.43

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Solution

The fourth proportional to 65.20, 89.86 and 56.43 is: 77.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.20 : 89.86 = 56.43 : x
  2. Step 2: Convert to fraction form
    65.20/89.86 = 56.43/x
  3. Step 3: Cross multiply
    65.20x = 89.86 × 56.43
  4. Step 4: Simplify right side
    65.20x = 5,070.81
  5. Step 5: Solve for x
    x = 5,070.81/65.20
  6. Step 6: Final answer
    x = 77.77

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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.