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Finding the Fourth Proportional to 608.20, 839.46 and 387.40

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Solution

The fourth proportional to 608.20, 839.46 and 387.40 is: 534.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    608.20 : 839.46 = 387.40 : x
  2. Step 2: Convert to fraction form
    608.20/839.46 = 387.40/x
  3. Step 3: Cross multiply
    608.20x = 839.46 × 387.40
  4. Step 4: Simplify right side
    608.20x = 325,206.80
  5. Step 5: Solve for x
    x = 325,206.80/608.20
  6. Step 6: Final answer
    x = 534.70

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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.