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Finding the Fourth Proportional to 47.42, 71.21 and 42.45

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Solution

The fourth proportional to 47.42, 71.21 and 42.45 is: 63.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.42 : 71.21 = 42.45 : x
  2. Step 2: Convert to fraction form
    47.42/71.21 = 42.45/x
  3. Step 3: Cross multiply
    47.42x = 71.21 × 42.45
  4. Step 4: Simplify right side
    47.42x = 3,022.65
  5. Step 5: Solve for x
    x = 3,022.65/47.42
  6. Step 6: Final answer
    x = 63.75

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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.