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Finding the Fourth Proportional to 838.34, 1,256.80 and 318.05

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Solution

The fourth proportional to 838.34, 1,256.80 and 318.05 is: 476.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.34 : 1,256.80 = 318.05 : x
  2. Step 2: Convert to fraction form
    838.34/1,256.80 = 318.05/x
  3. Step 3: Cross multiply
    838.34x = 1,256.80 × 318.05
  4. Step 4: Simplify right side
    838.34x = 399,723.65
  5. Step 5: Solve for x
    x = 399,723.65/838.34
  6. Step 6: Final answer
    x = 476.80

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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.