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Finding the Fourth Proportional to 687.81, 949.19 and 408.19

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Solution

The fourth proportional to 687.81, 949.19 and 408.19 is: 563.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.81 : 949.19 = 408.19 : x
  2. Step 2: Convert to fraction form
    687.81/949.19 = 408.19/x
  3. Step 3: Cross multiply
    687.81x = 949.19 × 408.19
  4. Step 4: Simplify right side
    687.81x = 387,445.45
  5. Step 5: Solve for x
    x = 387,445.45/687.81
  6. Step 6: Final answer
    x = 563.30

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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.