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Finding the Fourth Proportional to 485.71, 670.27 and 289.21

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Solution

The fourth proportional to 485.71, 670.27 and 289.21 is: 399.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.71 : 670.27 = 289.21 : x
  2. Step 2: Convert to fraction form
    485.71/670.27 = 289.21/x
  3. Step 3: Cross multiply
    485.71x = 670.27 × 289.21
  4. Step 4: Simplify right side
    485.71x = 193,848.79
  5. Step 5: Solve for x
    x = 193,848.79/485.71
  6. Step 6: Final answer
    x = 399.10

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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.