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Finding the Fourth Proportional to 1,069, 1,602.60 and 420.20

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Solution

The fourth proportional to 1,069, 1,602.60 and 420.20 is: 629.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,069 : 1,602.60 = 420.20 : x
  2. Step 2: Convert to fraction form
    1,069/1,602.60 = 420.20/x
  3. Step 3: Cross multiply
    1,069x = 1,602.60 × 420.20
  4. Step 4: Simplify right side
    1,069x = 673,412.52
  5. Step 5: Solve for x
    x = 673,412.52/1,069
  6. Step 6: Final answer
    x = 629.95

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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.