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Finding the Fourth Proportional to 768.40, 1,038.15 and 768.40

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Solution

The fourth proportional to 768.40, 1,038.15 and 768.40 is: 1,038.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.40 : 1,038.15 = 768.40 : x
  2. Step 2: Convert to fraction form
    768.40/1,038.15 = 768.40/x
  3. Step 3: Cross multiply
    768.40x = 1,038.15 × 768.40
  4. Step 4: Simplify right side
    768.40x = 797,714.46
  5. Step 5: Solve for x
    x = 797,714.46/768.40
  6. Step 6: Final answer
    x = 1,038.15

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Why These Related Problems?

These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.