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Finding the Fourth Proportional to 815.99, 1,221.09 and 507.99

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Solution

The fourth proportional to 815.99, 1,221.09 and 507.99 is: 760.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.99 : 1,221.09 = 507.99 : x
  2. Step 2: Convert to fraction form
    815.99/1,221.09 = 507.99/x
  3. Step 3: Cross multiply
    815.99x = 1,221.09 × 507.99
  4. Step 4: Simplify right side
    815.99x = 620,301.51
  5. Step 5: Solve for x
    x = 620,301.51/815.99
  6. Step 6: Final answer
    x = 760.18

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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.