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Finding the Fourth Proportional to 305.30, 421.20 and 207.08

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Solution

The fourth proportional to 305.30, 421.20 and 207.08 is: 285.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.30 : 421.20 = 207.08 : x
  2. Step 2: Convert to fraction form
    305.30/421.20 = 207.08/x
  3. Step 3: Cross multiply
    305.30x = 421.20 × 207.08
  4. Step 4: Simplify right side
    305.30x = 87,222.10
  5. Step 5: Solve for x
    x = 87,222.10/305.30
  6. Step 6: Final answer
    x = 285.69

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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.