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Finding the Fourth Proportional to 478.15, 659.81 and 289.09

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Solution

The fourth proportional to 478.15, 659.81 and 289.09 is: 398.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.15 : 659.81 = 289.09 : x
  2. Step 2: Convert to fraction form
    478.15/659.81 = 289.09/x
  3. Step 3: Cross multiply
    478.15x = 659.81 × 289.09
  4. Step 4: Simplify right side
    478.15x = 190,746.02
  5. Step 5: Solve for x
    x = 190,746.02/478.15
  6. Step 6: Final answer
    x = 398.93

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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.