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Finding the Fourth Proportional to 75.65, 104.40 and 42.90

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Solution

The fourth proportional to 75.65, 104.40 and 42.90 is: 59.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.65 : 104.40 = 42.90 : x
  2. Step 2: Convert to fraction form
    75.65/104.40 = 42.90/x
  3. Step 3: Cross multiply
    75.65x = 104.40 × 42.90
  4. Step 4: Simplify right side
    75.65x = 4,478.88
  5. Step 5: Solve for x
    x = 4,478.88/75.65
  6. Step 6: Final answer
    x = 59.20

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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.