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Finding the Fourth Proportional to 515.21, 710.99 and 305.42

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Solution

The fourth proportional to 515.21, 710.99 and 305.42 is: 421.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.21 : 710.99 = 305.42 : x
  2. Step 2: Convert to fraction form
    515.21/710.99 = 305.42/x
  3. Step 3: Cross multiply
    515.21x = 710.99 × 305.42
  4. Step 4: Simplify right side
    515.21x = 217,145.48
  5. Step 5: Solve for x
    x = 217,145.48/515.21
  6. Step 6: Final answer
    x = 421.47

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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.