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Finding the Fourth Proportional to 305.68, 421.68 and 285.04

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Solution

The fourth proportional to 305.68, 421.68 and 285.04 is: 393.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.68 : 421.68 = 285.04 : x
  2. Step 2: Convert to fraction form
    305.68/421.68 = 285.04/x
  3. Step 3: Cross multiply
    305.68x = 421.68 × 285.04
  4. Step 4: Simplify right side
    305.68x = 120,195.67
  5. Step 5: Solve for x
    x = 120,195.67/305.68
  6. Step 6: Final answer
    x = 393.21

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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.