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Finding the Fourth Proportional to 915.07, 1,370.55 and 427.09

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Solution

The fourth proportional to 915.07, 1,370.55 and 427.09 is: 639.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    915.07 : 1,370.55 = 427.09 : x
  2. Step 2: Convert to fraction form
    915.07/1,370.55 = 427.09/x
  3. Step 3: Cross multiply
    915.07x = 1,370.55 × 427.09
  4. Step 4: Simplify right side
    915.07x = 585,348.20
  5. Step 5: Solve for x
    x = 585,348.20/915.07
  6. Step 6: Final answer
    x = 639.68

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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.