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Finding the Fourth Proportional to 785.65, 1,084.20 and 491.09

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Solution

The fourth proportional to 785.65, 1,084.20 and 491.09 is: 677.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.65 : 1,084.20 = 491.09 : x
  2. Step 2: Convert to fraction form
    785.65/1,084.20 = 491.09/x
  3. Step 3: Cross multiply
    785.65x = 1,084.20 × 491.09
  4. Step 4: Simplify right side
    785.65x = 532,438.42
  5. Step 5: Solve for x
    x = 532,438.42/785.65
  6. Step 6: Final answer
    x = 677.71

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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.