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Finding the Fourth Proportional to 515.09, 710.78 and 282.21

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Solution

The fourth proportional to 515.09, 710.78 and 282.21 is: 389.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.09 : 710.78 = 282.21 : x
  2. Step 2: Convert to fraction form
    515.09/710.78 = 282.21/x
  3. Step 3: Cross multiply
    515.09x = 710.78 × 282.21
  4. Step 4: Simplify right side
    515.09x = 200,587.81
  5. Step 5: Solve for x
    x = 200,587.81/515.09
  6. Step 6: Final answer
    x = 389.43

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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.