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Finding the Fourth Proportional to 915.45, 1,369.12 and 813.39

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Solution

The fourth proportional to 915.45, 1,369.12 and 813.39 is: 1,216.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    915.45 : 1,369.12 = 813.39 : x
  2. Step 2: Convert to fraction form
    915.45/1,369.12 = 813.39/x
  3. Step 3: Cross multiply
    915.45x = 1,369.12 × 813.39
  4. Step 4: Simplify right side
    915.45x = 1,113,619.64
  5. Step 5: Solve for x
    x = 1,113,619.64/915.45
  6. Step 6: Final answer
    x = 1,216.48

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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.