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Finding the Fourth Proportional to 949.28, 1,308.82 and 687.20

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Solution

The fourth proportional to 949.28, 1,308.82 and 687.20 is: 947.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    949.28 : 1,308.82 = 687.20 : x
  2. Step 2: Convert to fraction form
    949.28/1,308.82 = 687.20/x
  3. Step 3: Cross multiply
    949.28x = 1,308.82 × 687.20
  4. Step 4: Simplify right side
    949.28x = 899,421.10
  5. Step 5: Solve for x
    x = 899,421.10/949.28
  6. Step 6: Final answer
    x = 947.48

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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.