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Finding the Fourth Proportional to 842.20, 1,161.78 and 609.40

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Solution

The fourth proportional to 842.20, 1,161.78 and 609.40 is: 840.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.20 : 1,161.78 = 609.40 : x
  2. Step 2: Convert to fraction form
    842.20/1,161.78 = 609.40/x
  3. Step 3: Cross multiply
    842.20x = 1,161.78 × 609.40
  4. Step 4: Simplify right side
    842.20x = 707,988.73
  5. Step 5: Solve for x
    x = 707,988.73/842.20
  6. Step 6: Final answer
    x = 840.64

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1.5x scale

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.