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Finding the Fourth Proportional to 768.34, 1,056.40 and 689.10

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Solution

The fourth proportional to 768.34, 1,056.40 and 689.10 is: 947.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.34 : 1,056.40 = 689.10 : x
  2. Step 2: Convert to fraction form
    768.34/1,056.40 = 689.10/x
  3. Step 3: Cross multiply
    768.34x = 1,056.40 × 689.10
  4. Step 4: Simplify right side
    768.34x = 727,965.24
  5. Step 5: Solve for x
    x = 727,965.24/768.34
  6. Step 6: Final answer
    x = 947.45

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.