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Finding the Fourth Proportional to 815.16, 1,219.72 and 717.20

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Solution

The fourth proportional to 815.16, 1,219.72 and 717.20 is: 1,073.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.16 : 1,219.72 = 717.20 : x
  2. Step 2: Convert to fraction form
    815.16/1,219.72 = 717.20/x
  3. Step 3: Cross multiply
    815.16x = 1,219.72 × 717.20
  4. Step 4: Simplify right side
    815.16x = 874,783.18
  5. Step 5: Solve for x
    x = 874,783.18/815.16
  6. Step 6: Final answer
    x = 1,073.14

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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.