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Finding the Fourth Proportional to 76.70, 114.91 and 42.40

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Solution

The fourth proportional to 76.70, 114.91 and 42.40 is: 63.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.70 : 114.91 = 42.40 : x
  2. Step 2: Convert to fraction form
    76.70/114.91 = 42.40/x
  3. Step 3: Cross multiply
    76.70x = 114.91 × 42.40
  4. Step 4: Simplify right side
    76.70x = 4,871.84
  5. Step 5: Solve for x
    x = 4,871.84/76.70
  6. Step 6: Final answer
    x = 63.52

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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.