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Finding the Fourth Proportional to 909.75, 1,364.80 and 389.75

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Solution

The fourth proportional to 909.75, 1,364.80 and 389.75 is: 584.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.75 : 1,364.80 = 389.75 : x
  2. Step 2: Convert to fraction form
    909.75/1,364.80 = 389.75/x
  3. Step 3: Cross multiply
    909.75x = 1,364.80 × 389.75
  4. Step 4: Simplify right side
    909.75x = 531,930.80
  5. Step 5: Solve for x
    x = 531,930.80/909.75
  6. Step 6: Final answer
    x = 584.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.