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Finding the Fourth Proportional to 830.78, 1,243.80 and 748.70

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Solution

The fourth proportional to 830.78, 1,243.80 and 748.70 is: 1,120.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.78 : 1,243.80 = 748.70 : x
  2. Step 2: Convert to fraction form
    830.78/1,243.80 = 748.70/x
  3. Step 3: Cross multiply
    830.78x = 1,243.80 × 748.70
  4. Step 4: Simplify right side
    830.78x = 931,233.06
  5. Step 5: Solve for x
    x = 931,233.06/830.78
  6. Step 6: Final answer
    x = 1,120.91

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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.