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Finding the Fourth Proportional to 699.20, 964.88 and 388.70

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Solution

The fourth proportional to 699.20, 964.88 and 388.70 is: 536.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.20 : 964.88 = 388.70 : x
  2. Step 2: Convert to fraction form
    699.20/964.88 = 388.70/x
  3. Step 3: Cross multiply
    699.20x = 964.88 × 388.70
  4. Step 4: Simplify right side
    699.20x = 375,048.86
  5. Step 5: Solve for x
    x = 375,048.86/699.20
  6. Step 6: Final answer
    x = 536.40

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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.