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Finding the Fourth Proportional to 810.32, 1,215.64 and 415.22

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Solution

The fourth proportional to 810.32, 1,215.64 and 415.22 is: 622.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.32 : 1,215.64 = 415.22 : x
  2. Step 2: Convert to fraction form
    810.32/1,215.64 = 415.22/x
  3. Step 3: Cross multiply
    810.32x = 1,215.64 × 415.22
  4. Step 4: Simplify right side
    810.32x = 504,758.04
  5. Step 5: Solve for x
    x = 504,758.04/810.32
  6. Step 6: Final answer
    x = 622.91

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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.