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Finding the Fourth Proportional to 419.21, 578.81 and 279.66

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Solution

The fourth proportional to 419.21, 578.81 and 279.66 is: 386.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.21 : 578.81 = 279.66 : x
  2. Step 2: Convert to fraction form
    419.21/578.81 = 279.66/x
  3. Step 3: Cross multiply
    419.21x = 578.81 × 279.66
  4. Step 4: Simplify right side
    419.21x = 161,867.11
  5. Step 5: Solve for x
    x = 161,867.11/419.21
  6. Step 6: Final answer
    x = 386.12

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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.