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Finding the Fourth Proportional to 783.64, 1,081.42 and 489.07

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Solution

The fourth proportional to 783.64, 1,081.42 and 489.07 is: 674.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.64 : 1,081.42 = 489.07 : x
  2. Step 2: Convert to fraction form
    783.64/1,081.42 = 489.07/x
  3. Step 3: Cross multiply
    783.64x = 1,081.42 × 489.07
  4. Step 4: Simplify right side
    783.64x = 528,890.21
  5. Step 5: Solve for x
    x = 528,890.21/783.64
  6. Step 6: Final answer
    x = 674.91

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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.