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Finding the Fourth Proportional to 30.91, 46.10 and 28.21

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Solution

The fourth proportional to 30.91, 46.10 and 28.21 is: 42.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.91 : 46.10 = 28.21 : x
  2. Step 2: Convert to fraction form
    30.91/46.10 = 28.21/x
  3. Step 3: Cross multiply
    30.91x = 46.10 × 28.21
  4. Step 4: Simplify right side
    30.91x = 1,300.48
  5. Step 5: Solve for x
    x = 1,300.48/30.91
  6. Step 6: Final answer
    x = 42.07

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.