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Finding the Fourth Proportional to 920.96, 1,270.80 and 688.64

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Solution

The fourth proportional to 920.96, 1,270.80 and 688.64 is: 950.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.96 : 1,270.80 = 688.64 : x
  2. Step 2: Convert to fraction form
    920.96/1,270.80 = 688.64/x
  3. Step 3: Cross multiply
    920.96x = 1,270.80 × 688.64
  4. Step 4: Simplify right side
    920.96x = 875,123.71
  5. Step 5: Solve for x
    x = 875,123.71/920.96
  6. Step 6: Final answer
    x = 950.23

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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.