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Finding the Fourth Proportional to 515, 772.50 and 287

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Solution

The fourth proportional to 515, 772.50 and 287 is: 430.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    515 : 772.50 = 287 : x
  2. Step 2: Convert to fraction form
    515/772.50 = 287/x
  3. Step 3: Cross multiply
    515x = 772.50 × 287
  4. Step 4: Simplify right side
    515x = 221,707.50
  5. Step 5: Solve for x
    x = 221,707.50/515
  6. Step 6: Final answer
    x = 430.50

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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.