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Finding the Fourth Proportional to 785.43, 1,084.58 and 491.20

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Solution

The fourth proportional to 785.43, 1,084.58 and 491.20 is: 678.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.43 : 1,084.58 = 491.20 : x
  2. Step 2: Convert to fraction form
    785.43/1,084.58 = 491.20/x
  3. Step 3: Cross multiply
    785.43x = 1,084.58 × 491.20
  4. Step 4: Simplify right side
    785.43x = 532,745.70
  5. Step 5: Solve for x
    x = 532,745.70/785.43
  6. Step 6: Final answer
    x = 678.29

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1.5x scale

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.