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Finding the Fourth Proportional to 838.40, 1,257.60 and 830.30

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Solution

The fourth proportional to 838.40, 1,257.60 and 830.30 is: 1,245.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.40 : 1,257.60 = 830.30 : x
  2. Step 2: Convert to fraction form
    838.40/1,257.60 = 830.30/x
  3. Step 3: Cross multiply
    838.40x = 1,257.60 × 830.30
  4. Step 4: Simplify right side
    838.40x = 1,044,185.28
  5. Step 5: Solve for x
    x = 1,044,185.28/838.40
  6. Step 6: Final answer
    x = 1,245.45

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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.