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Finding the Fourth Proportional to 75, 112.50 and 42.50

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Solution

The fourth proportional to 75, 112.50 and 42.50 is: 63.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    75 : 112.50 = 42.50 : x
  2. Step 2: Convert to fraction form
    75/112.50 = 42.50/x
  3. Step 3: Cross multiply
    75x = 112.50 × 42.50
  4. Step 4: Simplify right side
    75x = 4,781.25
  5. Step 5: Solve for x
    x = 4,781.25/75
  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.