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Finding the Fourth Proportional to 861.39, 1,292.21 and 284.31

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Solution

The fourth proportional to 861.39, 1,292.21 and 284.31 is: 426.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.39 : 1,292.21 = 284.31 : x
  2. Step 2: Convert to fraction form
    861.39/1,292.21 = 284.31/x
  3. Step 3: Cross multiply
    861.39x = 1,292.21 × 284.31
  4. Step 4: Simplify right side
    861.39x = 367,386.80
  5. Step 5: Solve for x
    x = 367,386.80/861.39
  6. Step 6: Final answer
    x = 426.50

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Double scale
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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.