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Finding the Fourth Proportional to 817.50, 1,128.21 and 507

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Solution

The fourth proportional to 817.50, 1,128.21 and 507 is: 699.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.50 : 1,128.21 = 507 : x
  2. Step 2: Convert to fraction form
    817.50/1,128.21 = 507/x
  3. Step 3: Cross multiply
    817.50x = 1,128.21 × 507
  4. Step 4: Simplify right side
    817.50x = 572,002.47
  5. Step 5: Solve for x
    x = 572,002.47/817.50
  6. Step 6: Final answer
    x = 699.70

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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.