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Finding the Fourth Proportional to 615.90, 918.57 and 557.58

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Solution

The fourth proportional to 615.90, 918.57 and 557.58 is: 831.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.90 : 918.57 = 557.58 : x
  2. Step 2: Convert to fraction form
    615.90/918.57 = 557.58/x
  3. Step 3: Cross multiply
    615.90x = 918.57 × 557.58
  4. Step 4: Simplify right side
    615.90x = 512,176.26
  5. Step 5: Solve for x
    x = 512,176.26/615.90
  6. Step 6: Final answer
    x = 831.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.