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Finding the Fourth Proportional to 682.21, 940.78 and 420.18

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Solution

The fourth proportional to 682.21, 940.78 and 420.18 is: 579.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    682.21 : 940.78 = 420.18 : x
  2. Step 2: Convert to fraction form
    682.21/940.78 = 420.18/x
  3. Step 3: Cross multiply
    682.21x = 940.78 × 420.18
  4. Step 4: Simplify right side
    682.21x = 395,296.94
  5. Step 5: Solve for x
    x = 395,296.94/682.21
  6. Step 6: Final answer
    x = 579.44

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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.