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Finding the Fourth Proportional to 989.87, 1,482.57 and 578.39

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Solution

The fourth proportional to 989.87, 1,482.57 and 578.39 is: 866.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.87 : 1,482.57 = 578.39 : x
  2. Step 2: Convert to fraction form
    989.87/1,482.57 = 578.39/x
  3. Step 3: Cross multiply
    989.87x = 1,482.57 × 578.39
  4. Step 4: Simplify right side
    989.87x = 857,503.66
  5. Step 5: Solve for x
    x = 857,503.66/989.87
  6. Step 6: Final answer
    x = 866.28

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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.