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Finding the Fourth Proportional to 789.50, 1,089.64 and 479.18

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Solution

The fourth proportional to 789.50, 1,089.64 and 479.18 is: 661.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.50 : 1,089.64 = 479.18 : x
  2. Step 2: Convert to fraction form
    789.50/1,089.64 = 479.18/x
  3. Step 3: Cross multiply
    789.50x = 1,089.64 × 479.18
  4. Step 4: Simplify right side
    789.50x = 522,133.70
  5. Step 5: Solve for x
    x = 522,133.70/789.50
  6. Step 6: Final answer
    x = 661.35

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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.