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Finding the Fourth Proportional to 826.38, 1,239.18 and 278.40

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Solution

The fourth proportional to 826.38, 1,239.18 and 278.40 is: 417.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.38 : 1,239.18 = 278.40 : x
  2. Step 2: Convert to fraction form
    826.38/1,239.18 = 278.40/x
  3. Step 3: Cross multiply
    826.38x = 1,239.18 × 278.40
  4. Step 4: Simplify right side
    826.38x = 344,987.71
  5. Step 5: Solve for x
    x = 344,987.71/826.38
  6. Step 6: Final answer
    x = 417.47

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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.