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Finding the Fourth Proportional to 878.80, 1,317.38 and 439.78

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Solution

The fourth proportional to 878.80, 1,317.38 and 439.78 is: 659.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.80 : 1,317.38 = 439.78 : x
  2. Step 2: Convert to fraction form
    878.80/1,317.38 = 439.78/x
  3. Step 3: Cross multiply
    878.80x = 1,317.38 × 439.78
  4. Step 4: Simplify right side
    878.80x = 579,357.38
  5. Step 5: Solve for x
    x = 579,357.38/878.80
  6. Step 6: Final answer
    x = 659.26

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1.5x scale

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.