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Finding the Fourth Proportional to 611.18, 842.64 and 389.75

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Solution

The fourth proportional to 611.18, 842.64 and 389.75 is: 537.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.18 : 842.64 = 389.75 : x
  2. Step 2: Convert to fraction form
    611.18/842.64 = 389.75/x
  3. Step 3: Cross multiply
    611.18x = 842.64 × 389.75
  4. Step 4: Simplify right side
    611.18x = 328,417.16
  5. Step 5: Solve for x
    x = 328,417.16/611.18
  6. Step 6: Final answer
    x = 537.35

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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.