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Finding the Fourth Proportional to 1,005, 1,507.50 and 321

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Solution

The fourth proportional to 1,005, 1,507.50 and 321 is: 481.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,005 : 1,507.50 = 321 : x
  2. Step 2: Convert to fraction form
    1,005/1,507.50 = 321/x
  3. Step 3: Cross multiply
    1,005x = 1,507.50 × 321
  4. Step 4: Simplify right side
    1,005x = 483,907.50
  5. Step 5: Solve for x
    x = 483,907.50/1,005
  6. Step 6: Final answer
    x = 481.50

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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.