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Finding the Fourth Proportional to 854.80, 1,280.58 and 489.40

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Solution

The fourth proportional to 854.80, 1,280.58 and 489.40 is: 733.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    854.80 : 1,280.58 = 489.40 : x
  2. Step 2: Convert to fraction form
    854.80/1,280.58 = 489.40/x
  3. Step 3: Cross multiply
    854.80x = 1,280.58 × 489.40
  4. Step 4: Simplify right side
    854.80x = 626,715.85
  5. Step 5: Solve for x
    x = 626,715.85/854.80
  6. Step 6: Final answer
    x = 733.17

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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.