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Finding the Fourth Proportional to 587.80, 811.30 and 391.32

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Solution

The fourth proportional to 587.80, 811.30 and 391.32 is: 540.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    587.80 : 811.30 = 391.32 : x
  2. Step 2: Convert to fraction form
    587.80/811.30 = 391.32/x
  3. Step 3: Cross multiply
    587.80x = 811.30 × 391.32
  4. Step 4: Simplify right side
    587.80x = 317,477.92
  5. Step 5: Solve for x
    x = 317,477.92/587.80
  6. Step 6: Final answer
    x = 540.11

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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.