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Finding the Fourth Proportional to 785.92, 1,086.08 and 645.80

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Solution

The fourth proportional to 785.92, 1,086.08 and 645.80 is: 892.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.92 : 1,086.08 = 645.80 : x
  2. Step 2: Convert to fraction form
    785.92/1,086.08 = 645.80/x
  3. Step 3: Cross multiply
    785.92x = 1,086.08 × 645.80
  4. Step 4: Simplify right side
    785.92x = 701,390.46
  5. Step 5: Solve for x
    x = 701,390.46/785.92
  6. Step 6: Final answer
    x = 892.45

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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.