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Finding the Fourth Proportional to 826.30, 1,239.31 and 278.43

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Solution

The fourth proportional to 826.30, 1,239.31 and 278.43 is: 417.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.30 : 1,239.31 = 278.43 : x
  2. Step 2: Convert to fraction form
    826.30/1,239.31 = 278.43/x
  3. Step 3: Cross multiply
    826.30x = 1,239.31 × 278.43
  4. Step 4: Simplify right side
    826.30x = 345,061.08
  5. Step 5: Solve for x
    x = 345,061.08/826.30
  6. Step 6: Final answer
    x = 417.60

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Double scale
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1.5x scale

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.