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Finding the Fourth Proportional to 50.87, 70.21 and 31.21

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Solution

The fourth proportional to 50.87, 70.21 and 31.21 is: 43.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    50.87 : 70.21 = 31.21 : x
  2. Step 2: Convert to fraction form
    50.87/70.21 = 31.21/x
  3. Step 3: Cross multiply
    50.87x = 70.21 × 31.21
  4. Step 4: Simplify right side
    50.87x = 2,191.25
  5. Step 5: Solve for x
    x = 2,191.25/50.87
  6. Step 6: Final answer
    x = 43.08

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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.