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Finding the Fourth Proportional to 860.36, 1,289.30 and 421.27

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Solution

The fourth proportional to 860.36, 1,289.30 and 421.27 is: 631.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.36 : 1,289.30 = 421.27 : x
  2. Step 2: Convert to fraction form
    860.36/1,289.30 = 421.27/x
  3. Step 3: Cross multiply
    860.36x = 1,289.30 × 421.27
  4. Step 4: Simplify right side
    860.36x = 543,138.08
  5. Step 5: Solve for x
    x = 543,138.08/860.36
  6. Step 6: Final answer
    x = 631.30

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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.