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Finding the Fourth Proportional to 688.70, 950.40 and 393.95

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Solution

The fourth proportional to 688.70, 950.40 and 393.95 is: 543.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.70 : 950.40 = 393.95 : x
  2. Step 2: Convert to fraction form
    688.70/950.40 = 393.95/x
  3. Step 3: Cross multiply
    688.70x = 950.40 × 393.95
  4. Step 4: Simplify right side
    688.70x = 374,405.33
  5. Step 5: Solve for x
    x = 374,405.33/688.70
  6. Step 6: Final answer
    x = 543.64

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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.