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Finding the Fourth Proportional to 611.81, 917.91 and 407.18

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Solution

The fourth proportional to 611.81, 917.91 and 407.18 is: 610.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.81 : 917.91 = 407.18 : x
  2. Step 2: Convert to fraction form
    611.81/917.91 = 407.18/x
  3. Step 3: Cross multiply
    611.81x = 917.91 × 407.18
  4. Step 4: Simplify right side
    611.81x = 373,754.59
  5. Step 5: Solve for x
    x = 373,754.59/611.81
  6. Step 6: Final answer
    x = 610.90

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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.