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Finding the Fourth Proportional to 1,005.80, 1,509.10 and 389.34

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Solution

The fourth proportional to 1,005.80, 1,509.10 and 389.34 is: 584.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,005.80 : 1,509.10 = 389.34 : x
  2. Step 2: Convert to fraction form
    1,005.80/1,509.10 = 389.34/x
  3. Step 3: Cross multiply
    1,005.80x = 1,509.10 × 389.34
  4. Step 4: Simplify right side
    1,005.80x = 587,552.02
  5. Step 5: Solve for x
    x = 587,552.02/1,005.80
  6. Step 6: Final answer
    x = 584.16

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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.