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Finding the Fourth Proportional to 860.12, 1,289.03 and 420.69

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Solution

The fourth proportional to 860.12, 1,289.03 and 420.69 is: 630.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.12 : 1,289.03 = 420.69 : x
  2. Step 2: Convert to fraction form
    860.12/1,289.03 = 420.69/x
  3. Step 3: Cross multiply
    860.12x = 1,289.03 × 420.69
  4. Step 4: Simplify right side
    860.12x = 542,284.76
  5. Step 5: Solve for x
    x = 542,284.76/860.12
  6. Step 6: Final answer
    x = 630.48

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1.5x scale

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.