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Finding the Fourth Proportional to 486.30, 670.99 and 289.72

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Solution

The fourth proportional to 486.30, 670.99 and 289.72 is: 399.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.30 : 670.99 = 289.72 : x
  2. Step 2: Convert to fraction form
    486.30/670.99 = 289.72/x
  3. Step 3: Cross multiply
    486.30x = 670.99 × 289.72
  4. Step 4: Simplify right side
    486.30x = 194,394.42
  5. Step 5: Solve for x
    x = 194,394.42/486.30
  6. Step 6: Final answer
    x = 399.74

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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.