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Finding the Fourth Proportional to 684.90, 945.18 and 419.31

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Solution

The fourth proportional to 684.90, 945.18 and 419.31 is: 578.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.90 : 945.18 = 419.31 : x
  2. Step 2: Convert to fraction form
    684.90/945.18 = 419.31/x
  3. Step 3: Cross multiply
    684.90x = 945.18 × 419.31
  4. Step 4: Simplify right side
    684.90x = 396,323.43
  5. Step 5: Solve for x
    x = 396,323.43/684.90
  6. Step 6: Final answer
    x = 578.66

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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.