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Finding the Fourth Proportional to 76.14, 105.21 and 56.88

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Solution

The fourth proportional to 76.14, 105.21 and 56.88 is: 78.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.14 : 105.21 = 56.88 : x
  2. Step 2: Convert to fraction form
    76.14/105.21 = 56.88/x
  3. Step 3: Cross multiply
    76.14x = 105.21 × 56.88
  4. Step 4: Simplify right side
    76.14x = 5,984.34
  5. Step 5: Solve for x
    x = 5,984.34/76.14
  6. Step 6: Final answer
    x = 78.60

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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.