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Finding the Fourth Proportional to 916.40, 1,373.70 and 819.20

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Solution

The fourth proportional to 916.40, 1,373.70 and 819.20 is: 1,228.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    916.40 : 1,373.70 = 819.20 : x
  2. Step 2: Convert to fraction form
    916.40/1,373.70 = 819.20/x
  3. Step 3: Cross multiply
    916.40x = 1,373.70 × 819.20
  4. Step 4: Simplify right side
    916.40x = 1,125,335.04
  5. Step 5: Solve for x
    x = 1,125,335.04/916.40
  6. Step 6: Final answer
    x = 1,228.00

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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.