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Finding the Fourth Proportional to 815.10, 1,219.61 and 486.21

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Solution

The fourth proportional to 815.10, 1,219.61 and 486.21 is: 727.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.10 : 1,219.61 = 486.21 : x
  2. Step 2: Convert to fraction form
    815.10/1,219.61 = 486.21/x
  3. Step 3: Cross multiply
    815.10x = 1,219.61 × 486.21
  4. Step 4: Simplify right side
    815.10x = 592,987.79
  5. Step 5: Solve for x
    x = 592,987.79/815.10
  6. Step 6: Final answer
    x = 727.51

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1.5x scale

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.