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Finding the Fourth Proportional to 611.90, 918.16 and 287.22

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Solution

The fourth proportional to 611.90, 918.16 and 287.22 is: 430.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.90 : 918.16 = 287.22 : x
  2. Step 2: Convert to fraction form
    611.90/918.16 = 287.22/x
  3. Step 3: Cross multiply
    611.90x = 918.16 × 287.22
  4. Step 4: Simplify right side
    611.90x = 263,713.92
  5. Step 5: Solve for x
    x = 263,713.92/611.90
  6. Step 6: Final answer
    x = 430.98

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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.