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Finding the Fourth Proportional to 784.16, 1,175.78 and 345.39

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Solution

The fourth proportional to 784.16, 1,175.78 and 345.39 is: 517.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.16 : 1,175.78 = 345.39 : x
  2. Step 2: Convert to fraction form
    784.16/1,175.78 = 345.39/x
  3. Step 3: Cross multiply
    784.16x = 1,175.78 × 345.39
  4. Step 4: Simplify right side
    784.16x = 406,102.65
  5. Step 5: Solve for x
    x = 406,102.65/784.16
  6. Step 6: Final answer
    x = 517.88

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.