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Finding the Fourth Proportional to 842.81, 1,263.90 and 315.60

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Solution

The fourth proportional to 842.81, 1,263.90 and 315.60 is: 473.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.81 : 1,263.90 = 315.60 : x
  2. Step 2: Convert to fraction form
    842.81/1,263.90 = 315.60/x
  3. Step 3: Cross multiply
    842.81x = 1,263.90 × 315.60
  4. Step 4: Simplify right side
    842.81x = 398,883.28
  5. Step 5: Solve for x
    x = 398,883.28/842.81
  6. Step 6: Final answer
    x = 473.28

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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.