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Finding the Fourth Proportional to 1,545, 2,317.56 and 390.78

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Solution

The fourth proportional to 1,545, 2,317.56 and 390.78 is: 586.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,545 : 2,317.56 = 390.78 : x
  2. Step 2: Convert to fraction form
    1,545/2,317.56 = 390.78/x
  3. Step 3: Cross multiply
    1,545x = 2,317.56 × 390.78
  4. Step 4: Simplify right side
    1,545x = 905,656.10
  5. Step 5: Solve for x
    x = 905,656.10/1,545
  6. Step 6: Final answer
    x = 586.19

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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.