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Finding the Fourth Proportional to 1,397.88, 1,929.72 and 949.80

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Solution

The fourth proportional to 1,397.88, 1,929.72 and 949.80 is: 1,311.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,397.88 : 1,929.72 = 949.80 : x
  2. Step 2: Convert to fraction form
    1,397.88/1,929.72 = 949.80/x
  3. Step 3: Cross multiply
    1,397.88x = 1,929.72 × 949.80
  4. Step 4: Simplify right side
    1,397.88x = 1,832,848.06
  5. Step 5: Solve for x
    x = 1,832,848.06/1,397.88
  6. Step 6: Final answer
    x = 1,311.16

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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.