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Finding the Fourth Proportional to 618.30, 853.40 and 419.18

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Solution

The fourth proportional to 618.30, 853.40 and 419.18 is: 578.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.30 : 853.40 = 419.18 : x
  2. Step 2: Convert to fraction form
    618.30/853.40 = 419.18/x
  3. Step 3: Cross multiply
    618.30x = 853.40 × 419.18
  4. Step 4: Simplify right side
    618.30x = 357,724.99
  5. Step 5: Solve for x
    x = 357,724.99/618.30
  6. Step 6: Final answer
    x = 578.56

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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.