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Finding the Fourth Proportional to 912.50, 1,369.32 and 399.50

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Solution

The fourth proportional to 912.50, 1,369.32 and 399.50 is: 599.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.50 : 1,369.32 = 399.50 : x
  2. Step 2: Convert to fraction form
    912.50/1,369.32 = 399.50/x
  3. Step 3: Cross multiply
    912.50x = 1,369.32 × 399.50
  4. Step 4: Simplify right side
    912.50x = 547,043.34
  5. Step 5: Solve for x
    x = 547,043.34/912.50
  6. Step 6: Final answer
    x = 599.50

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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.