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Finding the Fourth Proportional to 305.37, 420.80 and 217.89

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Solution

The fourth proportional to 305.37, 420.80 and 217.89 is: 300.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.37 : 420.80 = 217.89 : x
  2. Step 2: Convert to fraction form
    305.37/420.80 = 217.89/x
  3. Step 3: Cross multiply
    305.37x = 420.80 × 217.89
  4. Step 4: Simplify right side
    305.37x = 91,687.02
  5. Step 5: Solve for x
    x = 91,687.02/305.37
  6. Step 6: Final answer
    x = 300.25

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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.