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Finding the Fourth Proportional to 419.40, 578.86 and 286.80

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Solution

The fourth proportional to 419.40, 578.86 and 286.80 is: 395.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.40 : 578.86 = 286.80 : x
  2. Step 2: Convert to fraction form
    419.40/578.86 = 286.80/x
  3. Step 3: Cross multiply
    419.40x = 578.86 × 286.80
  4. Step 4: Simplify right side
    419.40x = 166,017.05
  5. Step 5: Solve for x
    x = 166,017.05/419.40
  6. Step 6: Final answer
    x = 395.84

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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.