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Finding the Fourth Proportional to 860.55, 1,289.80 and 397.68

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Solution

The fourth proportional to 860.55, 1,289.80 and 397.68 is: 596.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.55 : 1,289.80 = 397.68 : x
  2. Step 2: Convert to fraction form
    860.55/1,289.80 = 397.68/x
  3. Step 3: Cross multiply
    860.55x = 1,289.80 × 397.68
  4. Step 4: Simplify right side
    860.55x = 512,927.66
  5. Step 5: Solve for x
    x = 512,927.66/860.55
  6. Step 6: Final answer
    x = 596.05

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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.