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Finding the Fourth Proportional to 485.89, 670.59 and 289.42

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Solution

The fourth proportional to 485.89, 670.59 and 289.42 is: 399.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.89 : 670.59 = 289.42 : x
  2. Step 2: Convert to fraction form
    485.89/670.59 = 289.42/x
  3. Step 3: Cross multiply
    485.89x = 670.59 × 289.42
  4. Step 4: Simplify right side
    485.89x = 194,080.48
  5. Step 5: Solve for x
    x = 194,080.48/485.89
  6. Step 6: Final answer
    x = 399.44

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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.